How should I restore modified windows files?

[YouSuck]

I downloaded a theme and applied it and it changed the entire look of my desktop. Everything.

Now I applied another theme and nothing happened. Nothing changed.

This thing sucks.

I have run 'sfc /scannow' but even that thing didn't helped me.

Can someone here help me?

Much appreciated

[cooky560 Veteran]

Insert your Windows CD, and then trying running sfc /scannow

or if you really want to, and don't own an OEM CD, insert your Windows CD and choose 'Repair Install'

sfc /scannow must be executed using an elevated command prompt. Search for "cmd.exe" right click it, and choose "Run as Administrator" (Vista and Windows 7 Only)