Windows 7 - Blocky pixels in DVD movies

Please i'd like a help here,

It's been a month i bought a genuine Windows 7 Pro 64bit and lately i noticed that my DVD movies are not playing in a perfect quality, the picture is not smooth at all blocky pixels everywhere. I have used a non-genuine Windows 7 Ultimate 64bit before this (i know that's illegal that's why i got a genuine) and the movies were displaying awesomly.

I own a Cyberlink PowerDVD Ultra 10 and still no quality enhancements, i have all the newest drivers for all my hardwares. I used shark007 codecs it dindn't help much.

i really like to know what is the problem here, is it Windows or my ATI?

waiting for any useful help
thank you

Most likely you need to update your Video drivers. Current release for ATI products is version 11.1

thank you for the reply, actually i have installed ATI's drivers ver 11.1 but i took the files from the Sapphire website cause my Radeon HD5850 is manufactred by Sapphire, i will try downloading the drivers from AMD's site if that will help.

i'll be posting again

The drivers from saphire would be the same drivers.

If you choose to disable the Microsoft Video decoder on the SWAP TAB,
alternate codecs installed by my software will be used to decode DVD's.

Also know, the 64bit app only controls 64bit players such as Media Center
the 32bit app of course only affects playback in 32bit players.

thank you Shark007 for all the help, eveything is fine now i noticed those blocky pixels are showing up only when i put low quality or medium quality saved DVDs