Technical.Net

http://searchvb.techtarget.com/vsnetTip/1,293823,sid8_gci930036_tax293033,00.html

Configure ASP.NET 1.1 for the Application
When ASP.NET 1.0 is configured on the root Web site, follow these steps to configure ASP.NET 1.1 to run an application:1. Click Start, and then click Run. In the Open text box, type cmd, and then click OK.
2. At the command prompt, locate the following directory path:
%WindowsDirectory%\Microsoft.NET\Framework\v1.1.4322
3. If ASP.NET 1.1 is not already registered, type the following command to register it:
aspnet_regiis -ir
Note The -ir option registers ASP.NET 1.1 without updating the scripts in IIS.
4. Type the following to configure the ASP.NET 1.1 application in IIS:
aspnet_regiis -s w3svc/1/root/ApplicationName
To remove ASP.NET 1.1 from this application, repeat steps 1 and 2, and then type the following command:
aspnet_regiis -k w3svc/1/root/ApplicationName


how to run asp.net on XP machine.
- install .Net sdk 1.1
- reboot the machine
- go to .net command prompt
- run aspnet_regiis -i
- restart iis
- should see aspx in the configuration
- now VS should open asp.net application