|OK, then there must be something wrong in Windows. |
Have you ever been able to run the things you mention in full screen without a problem ?
Does your laptop still have it's original brand name software installation, or have you re-loaded Windows from a regular Windows DVD ?
Have you re-loaded the video "drivers", or have you loaded a newer version of them?
What size is your C partition and how much free space is left on it ?
Which anti-malware programs have you installed on your computer ?
Is your hard drive activity led on a lot, a lot more than it used to be ?
Do you have media sharing enabled in Windows Media Player 10 or 11 ?
How much ram is installed ?
Have you increased the amount of ram from what it originally had ?