Help Vista anti virus 2012 i got rid of it but its F... up my stuff read below?

Well i got malware bytes and deleted trojans and highjacket stuff and ended up having everything on my background play up i cant even install GAMES now wtf.... i get to install i click install it just doesnt go in anymore.... i doubleclick anything on my background it says which programe would you like to open it with wtf? i build pcs and programe them and this is a bad glitch with software i cant understand.... would apreaciate some good help with this to fix it :)