Samer Kanji: From what I get from your post, the sound driver may be the wrong driver or is install incorrectly and is creating a conflict. You should uninstall the driver.
Try to start the computer in Safe Mode.
Usually tapping F8 key during the memory check will give you the Safe Mode Option.
If you can boot in safe mode, Do this:

click Start/Control Panel/Add Remove Programs.
Select the sound driver from the list, then click Remove.
After it is uninstalled, restart the computer to see if it will boot Windows normally.
Next, if you are sure that you have the right driver for your sound card, try again to reinstall the driver.
You may have to repeat the several times until it works properly.
Best of Luck