Ok, so sorry in advance if this has been covered, but after reading allot I couldn't find anything similar.
 
Here is my issue. My gf had her computer fixed recently by a friend.  
It came back working perfectly, with vista inspirat 2.  
There were no issues everything was fully functional.
 
She doesn't really like Vista so today she decided to switch the theme in the display properties to regular XP.
 
The first time she ran it after that first shutdown explorer wouldn't boot, says there is an error.
 
After way to long reading a bunch of sites I stumbled on to the apparent fact that there are two explorer files and usually a virus will attack one. So using task manager run function i spent some time looking around only to find the second explorer was nowhere to be found.
 
Finally I found a 14_explorer file which i imagine is what happens to the second explorer once you install Inspirat 2. Or at least thats where my logic took me.  
 
So for kicks i tried to run it on safe mode to see if anything would change. Unfortunately that wasn't so. Explorer won't run even on safe mode.
 
What troubles me now is how safe it would be to uninstall Inspirat 2. And what that does to the 14_explorer file.  
 
I've since switched back to the Inspirat 2 theme but explorer still doesn't run.
She has no idea where the cd is so anything involving reformatting is kinda out.  
 
Oh and for some reason I can't access System restore either so that is out.
 
Any idea? I'm kinda running out.

why can't you go into system restore? that will solve almost any problem you are having. I would uninstall the bricopack if you don't like the theme and there are ways like reshacker which allow you to edit and delete resources from any type of file, but my money is on setting a restore point before the date when the computer broke or getting a copy of a friends system files and replacing the corrupt ones

Launch this through Task Manager and resrore to a point when everything worked:
%systemroot%\system32\restore\rstrui.exe