Hello, and good day.
I had the exactly same problems and nothing above anywhere in these forums worked for me. Until I tried this:
step 1: Create restore point
step 2: Go to Start > Run and type Regedit
step 3: Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion
step 4: Delete or modeify the Keys CSDBuildNumber and CSDVersion
Example of modify by name - (CSDBuildNumber -> CSDBuildNumber_old), same to other
Step 5: Install sp2 upgrade by downloading it using this link:
http://www.microsoft.com/downloads/detai...;DisplayLang=en
(Its is the network install file so its pretty large and its a must download!! Do not use windows update!!!):
And just like that... it worked. 9.0c, FINNALY. Try it, if you've exhausted all other resources.