Trouble getting it up and running

I am using XP SP2, .NET 1.1 (have 2 but want to use 1.1), and SQL Server 2005. I installed the latest version, let it use the defaults, chose Windows Auth (as it recommended) and on running it, I get the following error.

Cannot open database "CommunityServer" requested by the login. The login failed. Login failed for user 'UTB-DEV1\IUSR_UTB-DEV1'.

where UTB-DEV1 is my machine name.

I added UTB-DEV1\IUSR_UTB-DEV1 as a user under the CommunityServer database, and gave it just about every permission I could give it. But the error persists. Could someone give me any suggestions please?

Thanks in advance.

Regards,
Nish

Simple question first...Is SQL Server running on the same machine as the website?

Yes, I am trying this out on my local dev box - everything's on one machine. Anyway I uninstalled it and reinstalled it and chose Sql Server auth and now it works. Damn slow though. Most pages take 5-10 seconds to load. I am now on .NET 2.0 though. Anyway, that doesn't seem to be causing the terribly poor speeds.