Audio/Video playback issue

This is a problem that has plagued my laptop for some time now, but Im just now able to devote some time to trying to solve it.

Here goes. My computer has developed a problem with severe lag after its been running for a more than a few hours. The thing is, this lag only occurs whole something is being downloaded. The issue becomes worse the longer the computer runs. If I reboot the computer, the problem goes away, but only for a few hours, then the whole process starts again. Here is a video showing what this issue looks like while trying to play a video on youtube:
If I wait around and let the whole video load beforehand, it will play fine, but the video demonstrates what happens when you play the video while it is still loading.

At times, when the issue becomes serious enough, the screen will go black and my display drivers start to malfunction.

Heres what I have tried:
Downloading the latest drivers for my video card
Rolling back the drivers on my video card.
Replacing the memory modules (One of them had stopped working. Adding two new ones did not solve the problem)

As I said, this only happens when downloading, and only after the computer has been running for a few hours. Any ideas as to what could be causing this? Faulty gpu? Failing hard disk?

Thank you

Discussion is locked
Reply to: Audio/Video playback issue
PLEASE NOTE: Do not post advertisements, offensive materials, profanity, or personal attacks. Please remember to be considerate of other members. If you are new to the CNET Forums, please read our CNET Forums FAQ. All submitted content is subject to our Terms of Use.
Reporting: Audio/Video playback issue
This post has been flagged and will be reviewed by our staff. Thank you for helping us maintain CNET's great community.
Sorry, there was a problem flagging this post. Please try again now or at a later time.
If you believe this post is offensive or violates the CNET Forums' Usage policies, you can report it below (this will not automatically remove the post). Once reported, our moderators will be notified and the post will be reviewed.
- Collapse -
I don't see which Windows and no mention of canned air.

The missing details mean I'll use what you did reveal.

The fine for hours is a typical sign it's a machine that needs the usual canned air cleaning.

There's also some ISPs that slow down after a few hours of heavy use but only you may know your ISP and if they do that.

- Collapse -
Audio/Video playback issue

Hi, and thanks or the reply.
To clarify, I am running Windows 7 Home Premium
8gb DD3 1600 mhz ram (2 x 4gb)
Core i7 2630QM cpu
Nvidia GeForce GT 540M

Have not tried canned air
I doubt its the ISP since I dont have this issue on my other computers
Have not run memtest. Might actually run that later tonite.

- Collapse -
Those parts

Are now years old. If you haven't been doing the canned air then it's time to start.

- Collapse -
Canned air

Just to expand a little.
Get a can of compressed air give the innards and vents a cleaning.
Do this once a week for a month.

Since you had some kind of issue in this area it might be a good idea to grab a copy of memtest86 and let it fly for errors allowed.

CNET Forums