PRB: "The specified Web server is not running ASP.NET version 1.1" error message when you create an ASP.NET 1.1 application and you have both ASP.NET 1.1 and ASP.NET 1.0 installed
http://support.microsoft.com/Execute command:
(...)Microsoft.NET\Framework\v1.1.4322
[
aspnet_regiis.exe -i]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.
http://support.microsoft.com/?id=894435