ASP.NET, Web-Based Project Management Software Development Resource

Don’t pull your hair out with this running ASP.Net 1.1 and ASP.Net 2.0.  Apparently you cannot run ASP.Net 2.0 in 64 bit mode and run ASP.Net 1.1 in 32 bit mode at the same time with IIS 6.0.

 Here is some information from MS that I encountered that helped us to get ASP.Net 1.1 to work on x64:

From Microsoft Support:

IIS 6.0 supports both the 32-bit mode and the 64-bit mode. However IIS 6.0 does not support running both modes at the same time on a 64-bit version of Windows. ASP.NET 1.1 runs only in 32-bit mode. ASP.NET 2.0 runs in 32-bit mode or in 64-bit mode. Therefore, if you want to run ASP.NET 1.1 and ASP.NET 2.0 at the same time, you must run IIS in 32-bit mode

After you install the redistributable packages, you can switch between the different versions of ASP.NET. To do this, follow these steps for each ASP.NET version:

ASP.NET 1.1, 32-bit version
To run the 32-bit version of ASP.NET 1.1, follow these steps:

1. Click Start, click Run, type cmd, and then click OK.
2. Type the following command to enable the 32-bit mode:
cscript %SYSTEMDRIVE%\inetpub\adminscripts\adsutil.vbs SET W3SVC/AppPools/Enable32bitAppOnWin64 1
3. Type the following command to install the version of ASP.NET 1.1 and to install the script maps at the IIS root and under:
%SYSTEMROOT%\Microsoft.NET\Framework\v1.1.4322\aspnet_regiis.exe -i 
4. Make sure that the status of ASP.NET version 1.1.4322 is set to Allowed in the Web service extension list in Internet Information Services Manager.

ASP.NET 2.0, 32-bit version
To run the 32-bit version of ASP.NET 2.0, follow these steps:

1. Click Start, click Run, type cmd, and then click OK.
2. Type the following command to enable the 32-bit mode:
cscript %SYSTEMDRIVE%\inetpub\adminscripts\adsutil.vbs SET W3SVC/AppPools/Enable32bitAppOnWin64 1
3. Type the following command to install the version of ASP.NET 2.0 (32-bit) and to install the script maps at the IIS root and under:
%SYSTEMROOT%\Microsoft.NET\Framework\v2.0.40607\aspnet_regiis.exe -i -wow64 
4. Make sure that the status of ASP.NET version 2.0.40607 (32-bit) is set to Allowed in the Web service extension list in Internet Information Services Manager.

ASP.NET 2.0, 64-bit version
To run the 64-bit version of ASP.NET 2.0, follow these steps:

1. Click Start, click Run, type cmd, and then click OK.
2. Type the following command to disable the 32-bit mode:
cscript %SYSTEMDRIVE%\inetpub\adminscripts\adsutil.vbs SET W3SVC/AppPools/Enable32bitAppOnWin64 0
3. Type the following command to install the version of ASP.NET 2.0 and to install the script maps at the IIS root and under:
%SYSTEMROOT%\Microsoft.NET\Framework64\v2.0.40607\aspnet_regiis.exe -i 
4. Make sure that the status of ASP.NET version 2.0.40607 is set to Allowed in the Web service extension list in Internet Information Services Manager.
Note The build version of ASP.NET 2.0 may differ depending on what the currently released build version is. These steps are for build version 2.0.40607.

 How to switch between the 32-bit versions of ASP.NET 1.1 and the 64-bit version of ASP.NET 2.0 on a 64-bit version of Windows