Something that worked for me recently was going to Start>Control Panel>Add or Remove Programs and selecting Microsoft .Net Framework 1.1, 2.0, 3.0 and 3.5 and clicking Change/Remove then selecting Repair, one at a time. To discern how the SQL service is running click Start>Run and type in services.msc and go through the list. View properties of any item to see what logon it is using. If you need more detail or more tools (be careful though, it's a jungle in SQL) download Microsoft's SQL Management Studio Express for free here:
http://www.microsoft.com/downloads/...E3D-94B8-5A0F62BF7796&displaylang=en
