Microsoft DOES NOT SUPPORT asp.net 1.1 in 64bit mode, nor do they support MDAC in 64bit mode, so in order to use either MDAC (such as to connect to a microsoft access database)

Why you ask?  NO ONE KNOWS, but it is a pain.

Here's what you have to do:

Run the following from a dos prompt:
cscript c:\inetpub\adminscripts\adsutil.vbs SET W3SVC/AppPools/Enable32bitAppOnWin64 1

This enables IIS to run 32 bit apps (you can't run both 32bit and 64bit FYI).
Then you need to register ASP.NET to IIS
%SYSTEMROOT%\Microsoft.NET\Framework\v1.1.4322\aspnet_regiis.exe -i 
%SYSTEMROOT%\Microsoft.NET\Framework\v2.0.50727\aspnet_regiis.exe -i 
(You can't have 1 in 32bit more and one in 64bit, so you have to do both if you are using them.. and yes, this affects what you have to do when you are publishing, so go search google)
Also, change what is enabled in Web Server Extensions

Then, you will be able to connect your to access db or run an asp.net 1.1 application.

Enjoy!