Computer just hangs

[amgo_gnome]

I'm using Windows 7 Home Premium, Service pack 1

Processor: AMD A4-5300 APU with Radeon HD Graphics 3.40GHz

RAM: 4GB, 64bit OS

The problem I'm having that sometimes, usually shortly after it's been switched on, the computer just hangs, and catch-up TV programmes just freeze frame. This can last for anything from 5 up to 15 minutes. Sometimes, as this is happening, the screen seems to be flickering about a 100 times a second and similarly the Google Chrome icon zips up and down the task bar about 100 times a second. The mouse is inoperable during this time. Then eventually, maybe after 5 or 15 minutes, the computer will start running normally and the TV programme will resume. Can anyone advise what the problem might be please?

[Appzalien]

Sounds like a graphics issue to me but it could also be a memory issue as well. The simplest way to attempt a fix would be to go inside the PC (if it's a tower desktop type) and re-seat the memory sticks and graphics card if you have a card installed. Make sure the PC is totally powered down (like pulling the plug) when you do this. Another thing to check is your Device Manager for any errors there. Also a failing power supply could cause both memory and graphics to error or become unstable as well.

[amgo_gnome]

Thanks. I'm not too clued up on computers but I'll try the things you mention.