Need help on a dying netbook

My sister's old Netbook (Gateway EC1803u) has some issues with video playback... sound crashes and weird sounds get stuck on the speakers until I shut the browser down (usually happens on youtube). What could be causing this problem?? I've already restored Windows (Vista... I don't like that) about 3 times and this issue keeps coming back again and again. What can I do?

Slap on Linux! I'd recommend Mint.

Or update the browser/Flash. Or update drivers. Or do a fresh install. Or virus scan.

I've tried various Linux Distros, but none seem to be able to install correctly... I It is necessary to say that I want to be able to Dual-Boot the OS (since I might be selling the 'lil calculator down the road).

did you try downloading the latest drivers and flash update?

Some other generic PC-health stuff you could try: Run CCleaner, run Defraggler, run an antivirus (MSE might not work on Vista), make sure the hard drive isn't full to the brim, try Firefox in lieu of Chrome as it's a memory hog (just guessing you're on Chrome).

Use ubuntu its really light weight on netbooks,

my sisters acer aspire one had windows 7 on it for whatever reason and lagged like hell so I just un installed it and put on ubuntu 12.10 and it runs fineĀ 

Zorin OS Lite is also extremely light for netbooks

Got it in dual boot mode with Windows Vista/ Puppy Linux. This netbook has never been snapier than now.