HydroCAD^® Stormwater Modeling - Since 1986

Before you begin!

This page applies only to HydroCAD 10.1 and earlier!  License pooling is not required for HydroCAD 10.2 and later, which uses a new cloud-based license management system.  For simplified licensing and operation, we strongly recommend that you update to HydroCAD 10.2 as an alternative to the legacy license pooling mechanism.

License Pooling

You may share your HydroCAD license(s) on a network (subject to the terms of the License Agreement) by using the built-in "license pooling" mechanism.  This allows multiple users to share a smaller number of licenses.

Important: Under the terms of the license agreement, each license may be shared only on PC's at the physical site to which that license is registered.  Licenses may not be shared between multiple sites unless they are part of a special multi-site floating license.

Technical Requirements

The license pooling mechanism is part of the standard HydroCAD software and does not require any separate software.  License pooling requires only a shared network folder that is accessible to each PC that will use the license pool.  Other than standard file sharing, no other network protocols are employed.

License pooling is normally employed on a local network of Windows PC's, but may also be used on virtual or terminal environments by following the exact same instructions on this page.

Any deviation from these procedures and requirements will render the license pooling system inoperative and may put you in non-compliance with the HydroCAD license agreement.  Please follow these instructions carefully.

Setting up License Pooling

Step 1: Designate a shared network folder to contain the HydroCAD license information.  If a suitable folder doesn't already exist you can create a new one.  All HydroCAD users must have full read, write, and create rights to this folder, including the right to modify and delete files created by other users.  The folder must be accessible to all HydroCAD users by the same UNC (such as \\server1\hydrocad\license) or you can assign a drive letter and use a path (such as c:\hydrocad\license.)  All users must access the license folder by the exact same path or UNC; otherwise, the license pooling mechanism will fail.

If you are administering HydroCAD for multiple locations, you must use a separate license folder for each location.  You may not pool separate locations unless you have a multi-site floating license.

HydroCAD will automatically create and manage the files in this folder as required.  These files must never be modified or moved by hand, since this will render the license pool inoperative.  You do not need to install a "license file", which is created automatically by HydroCAD.

If you are deploying HydroCAD in a virtual or terminal environment, you must still designate a real, permanent license folder as described in this step.

Synchronized folders like DropBox and Google Drive can not be used for license pooling. These services work by synchronizing files after they have been updated, rather than providing simultaneous shared access to a common folder.

Step 2: Install HydroCAD on at least one PC.  Run the setup program and select "Standard Installation".  There is no separate "network installation".  Do not install the software on a server or shared drive.

If you are intending to deploy HydroCAD on a virtual or terminal environment, you must still perform at least one installation on a standard PC for the purposes of entering the license information in the next step.

Step 3: Start HydroCAD on any one PC.  The first time you run the program the serial number screen will appear automatically. (If the screen does not appear, open it by selecting Settings|Serial Number.)  Now click the Network button and select the license folder designated in step 1.  Then enter all the serial number(s) to be shared, each on a separate line.  You should also enter a password to protect your setup from inadvertent changes.  Finally, click Ok to save the serial numbers to the designated license folder.

After you click OK, examine the HydroCAD title bar to be sure it indicates the correct number of users and nodes.  If the information is correct you can exit from HydroCAD on this first PC.

Step 4: Install HydroCAD on each additional PC where it will be used.  Run the setup program and select "Standard Installation".

If you use a script for automatic installation on multiple computers you may use "setup /silent" to perform a silent installation on each PC.

If you are using a terminal or VM environment you can clone the working installation created in steps 2 and 3, including the applicable registry settings.  But remember that the license folder must never be copied or virtualized.  All installations must access the original, real, license folder and not a copy.

Step 5: Start HydroCAD on each additional PC.  When the serial number screen appears do not re-enter the serial numbers.  Instead, click the Network button and browse to the shared license folder designated in step 1.  When the license information is found, HydroCAD will run immediately without displaying the serial number screen.  You do not have to re-enter the serial number(s) or know the password in order to configure the additional systems - just select the license folder.

If HydroCAD doesn't recognize the serial numbers previously entered in step 3, stop and make sure you're using the exact same path or UNC used in step 3.  Do not re-enter the serial number(s) on subsequent PC's, since this behavior indicates a difference in the license paths that must be resolved in order to use license pooling.  For details see "Shared serial numbers not recognized", below.

If there will be multiple HydroCAD users on a given PC, repeat this step for each user login.

Administrators' tip:  You can automate this step by preloading the location of the license folder into the registry value HKCU\Software\HydroCAD\Settings\LicPath for each user.  This will allow HydroCAD to start without further prompting for license information.  You can also use this registry key to specify a hidden license folder that may not be visible with the Network button.

Starting with HydroCAD-10.0 build 17 you may preset a default license folder for all users in the string value HKLM\Software\HydroCAD\LicPath (on 32-bit systems) or HKLM\Software\Wow6432Node\HydroCAD\LicPath (on 64-bit systems).  Note that this value is a default value only for new users, and will not override any existing users, which must be individually updated.

If you are running HydroCAD in a VM and receive "warning 115 More recent serial number skipped", Windows may be misreporting the version number of the hydrocad.exe file. This can happen if you attempt to deploy HydroCAD without running the standard setup program and you don't provide the appropriate compatibility details in your deployment. Customers have reported good results using "installed-permanent layer 1" for the Windows VM.

Step 6: If you previously had any of your licenses dedicated to an individual PC, start HydroCAD on that PC, open the Settings|Serial Number screen, click the Network button, and select the network license folder designated in step 1.  This will cause that PC to use the shared license pool instead of the local license.

About the license file

Important: The license file must be established by entering the serial numbers through HydroCAD as described above.  For your security, the HydroCAD license information is stored in an encrypted file which is keyed to the drive where it is stored.  The license file will not be recognized if it is copied, moved, or deployed by any other means.  If you need to move the information to a new drive or server, click the Network button and select the new location.  If the file is moved by any other means it will no longer be recognized, and you will need to re-enter your serial numbers.

Moving the license file

If you replace the computer (server) where the license file is located, you can move the license file by clicking the HydroCAD Network button and selecting the new file location.  If the old license file is still accessible HydroCAD will automatically move the license information to the new folder.

Important: Since the license file is "keyed" to it's original file location, if the file is moved by any other means it will no longer be recognized by HydroCAD, and you will have to manually re-enter the serial numbers.

After moving the license file, start HydroCAD on each additional PC and select the new license folder.  You do not have to re-enter the serial numbers on the additional PC's - just select the new folder and HydroCAD will run immediately.

Administrators' tip:  If you prefer, you can designate the new license folder by updating the registry key HKCU\Software\HydroCAD\Settings\LicPath for each user.  This eliminates the need to launch HydroCAD on each PC.

Can you send me a license file?

No.  The license file is created and read only by HydroCAD as described above.  Because each file is locked to the drive on which it is created, no one else can read a file created on your system, or create a file that will be recognized on your system.  Furthermore, there is never any need to manage the license files by hand, since they are automatically created by HydroCAD based on the information entered on the Settings | Serial Number screen.

Shared serial numbers are not recognized?

If you are sharing your license(s) over a network, each PC must use the exact same drive letter or UNC name to access the license information.  This is displayed at the bottom of the Settings|Serial Number screen as shown in the red box at the right.  Using a different folder specification, even if it resolves to the same folder, will cause the license pooling to fail.  The specification is also case sensitive, so make sure the capitalization is identical on each PC.  If any PC is using a different folder specification, click the Network button and enter the correct details.

Each PC must also read the same volume label and drive serial number for the license folder.  If these details don't match, other computers will not be able to read the license file and will display an empty serial number form.  To verify the drive information, double-click the license path at the bottom of the Settings|Serial Number screen.  (Shown in the red box at the right.)  This will display a "Storage ID" like this:

    Storage ID = C:\ 24EA-8EBC Boot Drive

The storage ID normally consists of the drive letter (or UNC name), the drive serial number, and the volume label.  These parameters can be verified by executing a Windows VOL command on the drive letter or UNC name.  In rare cases, certain operating systems, servers, or file shares may omit one of these parameters, causing the HydroCAD license sharing to fail.

To share licenses between Windows 98 and later versions (XP, Vista, etc), open the Settings|Serial Number screen and uncheck the box labeled "Lock serial number(s) to disk drive".  You only need to make this change on the computer(s) that you will use to enter the serial numbers.  Set a password to prevent other computers from re-locking the serial number to the drive.

Note: For earlier versions of HydroCAD without this option, apply this registry patch to the PC(s) where you plan to enter the serial numbers.  (The patch does not need to be applied to other PCs.)  Then start HydroCAD on a patched PC and verify that all serial numbers are present.  Set a password to ensure that no one disturbs your setup.  When you click OK the title bar should show the correct user count.  All HydroCAD workstations should now be operable.

"Unable to create HydroCAD user file in [folder]"

This message indicates that HydroCAD was unable to create the required user file at startup.  This file is used to keep track of the number of people currently running HydroCAD.  The user file is created in the same folder used to store the HydroCAD serial number(s) as designated in step 1 above.  Each HydroCAD user must have full read, write, creation, and deletion rights to all files in this folder, including files created by other users.

This error can occur if:

1. The specified license folder no longer exists, -or-
2. You no longer have network access to the folder, -or-
3. You don't have write and delete access to the folder, -or-
4. The drive is full, preventing you from creating a new file.
5. There are file access issues on a Novell Netware server.

To correct the situation:

1. Restore full network access to the folder.
2. If the folder was deleted, re-create the folder.
3. If you cannot restore access to the folder, select the button to reset the license folder, or use this file to clear the registry setting.

You should now be able to start HydroCAD.  If no serial numbers are present in the license folder, the serial number screen will open automatically.  Re-enter your serial number(s), or click the Network button to select a different license folder.  If serial numbers are already present, you can use Settings|Serial Number to open the screen and change the license folder.

Note: The automatic license-sharing mechanism requires a license folder that is always available to each user.  If you enable license sharing for a laptop computer, you will only be able to run HydroCAD while it is connected to the network.  If you plan to run HydroCAD without a network connection, you must leave the license folder on a local drive and implement your own procedures to ensure that you don't exceed the maximum number of licensed users.

How do I recover my password?

The Settings|Serial Number screen includes the option to set a user-defined password.  We encourage the system administrator to set a password in order to prevent unauthorized changes to your license information.  This password is completely independent of any download password that may have been issued with your software.

If your password is lost or forgotten, it cannot be recovered.  However, you can reset your password by deleting the hydrocad.hcl file which is located in the shared license folder designated in Step 1, above. After deleting the file, start HydroCAD on any one PC and re-enter your serial number(s).  No changes are required to the individual HydroCAD installations, which should still be pointed to the original license folder and will run without further action as soon as the serial numbers have been re-entered from a single PC.   Details here.

[Home]   [Support] 

Copyright © 2025 HydroCAD Software Solutions LLC (privacy)   (legal notices)