nibnibz

hi
recently my computer has been having problems with .exe files, dont know how it started maybe a virus or something but AVG identified all .exe extensions for my programmes as threats and another virus scanner found them as "files not found", once this happened to a programme i was unable to access it and a windows restriction message came up. i did a virus scan and removed anything i could then restarted comp (bad idea probs =/) now when i start up my pc explorer doesnt load (even in safe mode) i cant do it via taskmanager->run prog->explorer because it gives a message "windows cannot find,"explorer". make sure you have typed the name correctly and try again". i have read on other threads that a virus could have changed my .exe directory in the registry (or something like that) and give instructions how to giude through regedit and fix it but i cant access regedit through the command prompt or by run->regedt32, if i type in run-> reg edit a box appears for a second then dissapears. ive tries doing this in safe mode too.

any help on fixing this would be appreciated, i am a bit of a noob though if you havnt already gathered ^^ so ya may have to dumb it down a bit lol.
if any more info is needed just ask plz