Re: Problem with SQL Server Express
Give write permission to ASPNET user and if using Win 2003 server also to IISWPG user for the Data folder and all child objects. After that, type a space in webconfig and save to restart the app.
Right click the folder and chose Properties, then the Security tab. If you don't see the security tab you need to enable simple file sharing. I don't remember off the top of my head where that setting is but google can find it.
Click the Add button then click Advanced then Find to find these users
Hope it helps,