Go here:
C:\Program Files (x86)\iTunes\
Copy the iTunes folder, within the folder you are in, out somewhere else. (I have no idea if this will actually restore your library statistics...)
Make sure iTunes is uninstalled.
Delete: C:\Program Files (x86)\iTunes\
(If 64bit, delete C:\Program Files\iTunes as well.)
Download:
http://www.piriform.com/ccleaner/download/standard
(During setup, when it comes to any page with check boxes, it's probably a better idea to uncheck almost all of them. Leave the shortcuts.)
Run the registry cleaner with everything selected 2~4 times, or until errors fail to appear.
Attempt an iTunes installation.
Open iTunes.
If it works:
Close iTunes.
Copy the iTunes folder, (C:\Program Files (x86)\iTunes\iTunes) within the folder you are in, out somewhere else. (Rename it so it doesn't merge with your previous one.)
Drag the first backup into iTunes folder, start iTunes. (Pray)
If that doesn't work, try to figure out more to do, otherwise put the old folder back and too bad.
p.s I don't use iTunes. goodluck.