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

http://support.microsoft.com/kb/894435

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.

Note If you have Microsoft Exchange Server 2007 installed on the computer, use the instructions for ASP.NET 2.0, 64-bit version.

Before you can switch between the different versions of ASP.NET, visit the following Microsoft Developer Network (MSDN) Web site to download and install both the .NET Framework 1.1 and the .NET Framework 2.0:

http://msdn2.microsoft.com/en-us/netframework/aa731542.aspx (http://msdn2.microsoft.com/en-us/netframework/aa731542.aspx)

For example, if you are running Microsoft Windows x64 Edition, download the following two redistributable packages:

• The .NET Framework Version 2.0 Redistributable Package x64 (64 Bit)
• The .NET Framework Version 1.1 Redistributable

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\v2.0.50727\aspnet_regiis.exe -i
4. Make sure that the status of ASP.NET version 2.0.50727 (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\v2.0.50727\aspnet_regiis.exe -i
4. Make sure that the status of ASP.NET version 2.0.50727 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 2.0.50727.