E6400 Hanging Problems

Hi all,
I have a dell E6400 from outlet for six months now. It was fine wid occassional hanging, DCP and other problems but nothing major.
Two days ago I started getting some major problems

1. 'SM Manager.exe has experienced an error and needs to be closed'. appears every time I log on.

2. Mozilla firefox crashed after that(maybe unrelated)

3. Yesterday was watching a video on youtube, suddenly it got stuck and some loud noise started coming.

From then on its been hanging ever since, every 5-10 min .

Will be grateful for some suggestions

 

update:

I did find there was no problems by running the hard disk and memory scan.

Figured it could be a virus problem (though avira didnt detect any virus).

Reinstalled XP and drivers and the laptop is fine.

Hope the information might be useful for someone else with similar problem(not the easiest solution but worked )