Video becomes distorted at times.

[Nagashi]

Hello. I just recently upgraded my video card from an ATI Radeon x1300 to an ATI Radeon HD 4850. I noticed that after installing this card and the latest drivers from the manufacturer's website, my videos would play fine for a while and then become distorted for a second or two, then go back to normal. This happens whenever I'm streaming a video online or when I'm watching a video with Media Player Classic Home Cinema or VLC. This doesn't happen to YouTube videos though nor does it happen while playing games on my PC. I've installed the latest flash drivers as well but it doesn't seem to make a difference. Any help or suggestions would be greatly appreciated.

[Nagashi]

I forgot to add that when I attempt to play a video with Media Player Classic or VLC, sometimes it'll play for a few seconds then freeze, then the screen'll go blank, and then I'll get this error saying "Display driver stopped responding and has recovered.

Additional Information:

ATI Radeon HD 4850 1 GB VRAM
Windows 7 Ultimate x86 32-bit Build 7600
ASROCK 775-DualVSTA
Intel Pentium D 3.40 + 3.42 GHz (not overclocked)
2 GB RAM, Direct X 11

[Nagashi]

Any info at all would be greatly appreciated.

[Nagashi]

After searching frantically for an answer via Google, I discovered that my ATI Radeon HD 4000 series video card doesn't support DirectX 11 which came preinstalled with Windows 7. Only ATI Radeon HD 5000 series cards support DirectX 11. Also, I am unable to uninstall or replace DirectX 11 with an older version. Everywhere I look I get the same answer. There's no way to replace it with an older version. Well, I don't believe it. There's got to be some way to install DirectX 10 over 11 in Windows 7. And I have no intention of downgrading back to Wiindows XP. Any help or suggestions would be greatly appreciated.........