Problems with macbook, 2008 model

My fiance's laptop is a 2008 model macbook. it has plenty of free HD space and 3 gigs of ram.

Over the last few months, we've had issues with iTunes freezing a lot when playing downloaded videos from itunes. After the issue comes up, everything else starts giving her problems, like safari or Chrome for web browsing.

I've reinstalled twice, restored once from a time machine back up. 2nd time with no time machine restoration.

I'm really have no clue at this point. I've used disk utility to verify the disk and repair permissions...no issues with either.

I don't know if its an issue with the iTunes software or with some piece of hardware. Should I try and replace the ram or HD? I don't really want to go buying new HD pieces if its not the issue. Nor do I want to pay someone to check it out.

I've run the apple hardware test from bootup, long version, and found no hardware issues. Is iTunes and software the crappy?


Any help is appreciated. Thanks. I don't feel a new computer is necessary.