Hard Drive Revs when videos play

While on FBook about a week ago, I found that when I run a video, the hard drive will rev faster and slower. Doesn't affect the video. Task manager doesn't report any increase in cpu usage. Computer runs fine, even during the event.

I ran malware bytes and superantispyware nothing found. I ran ccleaner and did a defrag too. Kept it offline for a few days, runs fine. Got online and did non video stuff, no problem.

Went over to run a news video, boom, the revving starts up.

So I'm thinking it is some form of malware. Anyone have any info to share about it?

I did look around for posts on this subject, but nothing obviously the same appeared.

This is an older laptop running XP, Firefox browser. AV is Avast (as MS stopped the support for MS Security Essentials at the same time they stopped supporting XP)



regards,

dkgoodwin