ASPNET user does not have write access to Temporary ASP.NET Files

Have you tried, the aspnet_regiis exe in the framework folder?

I had the same problem. This is what I did:

1. Go to c:\windows\microsoft.net\framework\v2.0.50727
2. right click on "Temporary ASP.NET files"
3. Security tab
4. Select "Users(xxxxxx\Users) from Group
5. check "Write"
6. OK

Either grant that user the level of access to that directory, or change the identity that the application's application pool runs under - in IIS Manager, determine what App Pool is used to run your application, then in the App Pool section of IIS Manager, look at the properties for that pool - the tab you want is "Identity" I think (this is off the top of my head).

You can set it to another user account - for example, Crystal Reports .Net requires update and delete access to C:\Temp - so we have a "webmaster" user, with administrator access, and use that identity for those applications.