how do i remove spyware?

my other computers desktop says:

"WARNING!
You're in Danger! Your Computer Is Infected With Spyware! All you do with computer is stored forever in your hard disk......
Secure Yourself Right Now! Remove All Spyware From Your PC!"

it wont let me open some things like the anti sumthin program that removes viruses, control panel etc.... , after like 10 min. it restarts by itself, and its REALLY slow so i cant really do anything before it restarts. how do i fix this?
thx
u guys arent much help.
its not a pop up message its my deskktop background and it doesnt let me change it. and i dont have time to download a software cuz it would restart.

You are infected with spyware if:

* You see too much pop-up advertisements.
* Your browser has toolbars that you haven't installed.
* Your homepage has changed (and you can't change it back).
* Other settings have changed without your permission.
* Your computer is slow.

To get rid of spyware and keep your computer clean you can use an antispyware or even more.
You can download a antispyware software. There are 10 good anti-spywares.
here is the reviews: http://top5antispywarereviews.com/

You can download one and scan your system.
All are safe and can be trusted.

Mobile Drive Secure Review

Tags: disk secure, windows live account, disk secure erase windows