Programs opening slowly

I have a Dell XPS 435T with Intel Core i7, 3GB DDR3 64-bit Win7 Home Premium.

My computer has been working fine for over the year that I've had it, though I was working on homework for one of my classes I thought I would update the program I was using to install an addon that would really help with my workflow (program: 3ds Max 2012, addon: Xoliul shader2).
After trying multiple times to get this to work I gave up thinking the program version just wouldn't work with it.

I'm not sure what other things I may have updated, but this seemed to be the source of my troubles. After restarting my computer everything went slower, and by slow I mean start up took about 5 minutes longer, Mozilla firefox takes about 2 minutes to fully open and actually start functioning. Any program will take 1-3 minutes to full get started on running or even start the loading to start. When I play any games since the problem they will run fine for about 10 minutes and during anything intense the computer locks up and freezes for 1-2 minutes.

I have felt pretty secure before this with my PC, I'm usually protected well enough with Microsoft Security Essentials and NoScipt, but this time I think I may have gotten something.

Any help would be very appreciated.