How do I change to Basic Windows 7 theme through command prompt?

I'm having problems with my computer...isn't everyone on this forum? (excluding all you experts of course) Anyway, I accidently changed the theme to Windows Classic and it prompted a very undesirable feature. None of the programs run through Windows Explorer will load! Control Panel, My Computer, Documents, Devices and Printers: A window will pop up, but no amount of waiting will load the contents. There is simply a black screen...or else a screen full of the background or of other windows that leave residue whenever you move them around. That last sentence didn't make much sense, sorry.
I've tried everything: running anti-malware and antivirus programs, I've done sns /scannow, I've tried every means in my power, google searched everything a million times and tried every suggestion. Nothing has changed. My dad (who is a computer programmer) also tried for a long while, with no results. I can't troubleshoot because Control Panel won't load, can't change theme, because Personalize won't load. In short, I'm stuck and please, oh please, help me!

This would get more attention in the general help forum. I would use the Advance Boot Options menu (press F8 just as Windows first begins to load) to:

go into Safe Mode. Try there to make the changes.
If not, then use "Last good configuration" option.
If not, try to revert to a System Restore point.