restoring Macbook with Time Machine - A few questions

So for a while now my macbook pro has been running sluggishly. Many java heavy websites, and some applications such as photoshop, word, and all games will give me the spinning wheel immediately after clicking them. Took my computer to the genius bar and was told to just reinstall mac OS. well I just received my new external in the mail today (old one crashed) and I decided to back up all my info using time machine. so my question is -- will time machine restore my computer back to the way it is now, still getting hung up on ram-heavy apps? or will it just restore my files? any suggestions for a better way to fix this problem? I was thinking about just saving my important files (music, photos, firefox settings, etc) and just starting completely fresh and loading all my media onto a fresh computer. would this be too much of a hassle? any input is helpful. thanks.

You could install the OS then use Migration Assistant to get your files back rather than everything, or you could use your Time Machine backup to restore your computer but then uninstall all the Apps that are causing the slow down.

Also have a look at a RAM upgrade if you haven't already maxed it out.

HTH
- Simon

I dont believe it is the RAM causing the slowdown although it seems like that would be why... When looking at the activity monitor it shows that my RAM (2GB) has 1.25 GB actively being used. I never had a problem before running any applications, just one day randomly things started freezing for no known reason. The people at the genius bar couldnt see anything hogging RAM in the activity montior, hence telling me to just reinstall MacOS to rid my computer of whatever must be causing the slowdown. What is this migration assistant you spoke of?

Migration Assistant is an option you get half way through OS installation so you can retrieve your files from another computer or backup. You can also access it through Applications > Utilities

HTH
- Simon