Vista startup problems? ?

HI guys, Im not much of a gearhead at these computers but i recently dealt with some problems, On my vista 32bit startup i can go onto the internet and let my programs load up for about 3 minutes than the whole pc almost locks over everything i touch freezes and i tried the startup repair but it doesnt finish without auto canceling itself out, i do not have any system saved restore points and i dont want to rollback to factory status due to this is also my sons computer and he plays many games and i have docuements on here i cant loss. Can someone help me out here? I know its not a driver related issue since last night i used it fine.
P.S I can run safemode with the internet fine thats how im posting this, But for our sound and other programs to work i need to be able to acess the main computer
Did Mercui and waynes help nothing yet

two things

1) If you can download ” Malwarebytes ” free version
Install it start safe mode and run it it should find the problem if it is a virus etc
2) Right click C: go to Properties / Tools / error repair
When new box pops up tick little box to repair errors and reboot.
Windows on rebooting will scan disk and fix any errors on it

If you do both the above in order 1 2 you should have your computer back

Auto Repair: Troubleshooting Starting Problems – 3 of 4