Whilst attempting to set up a work computer as a testbed I was going through the process of installing SQL Server 2005 server on XP. I had previously installed all of the components including IIS, .Net framework, etc. In the middle of the install, I got the following error:
SQL Server Setup failed to obtain system account information for the ASPNET account
To proceed, reinstall the .NET Framework, and then run SQL Server Setup again.
The problem is that the user ASPNET was not created at any of the previous installs. To create this user, I did the following (note that framework version may have a different version on your machine)
This creates the ASPNET account. After the account is created, SQL Server 2005 installed normally.
This tip was gleaned from: