I believe you have picked up a 'scareware rogue anti-virus'.
A new mutation of the old MS Antivirus,http://en.wikipedia.org/wiki/MS_Antivirus
Does not let you access any administrator privileges.
Control Panel, Task Manager, Administrator tasks, etc.
Blocks user privileges; Internet, Documents, etc.
Doesn't want you to get rid of it, lol!
Download the free version of Malwarebytes Anti-Malware from CNET, and kick it to the curb,http://download.cnet.com/Malwarebytes-Anti-Malware/3000-8022_4-10804572.html
Click on Download Now in the green rectangle.
(Has CNET Secure Download in it on the bottom)
Download to the computer you are using now, then copy it to a CD disk. Put the disk in the optical drive of the infected computer. (CD/DVD drive = Optical drive)
Install Malwarebytes. When finished there will be a Malwarebytes icon on your desktop screen. Double-click on it.
(If you need guidance in downloading, or installing Malwarebytes post in a Comment)
When Malwarebytes is running there will be pop-up, after pop-up.
So many in fact, you will not be able to see the entire Malwarebytes screen, and wonder if it is working.
IT IS, I assure you.
DO NOT click on the pop-ups, or you will just slow Malwarebytes down.
You will see pop-ups that look like genuine Windows 'shields', and fake ones also.
Clicking on the genuine Windows shields will do nothing anyway.
Average time for Malwarebytes to run is around 42 minutes. Just depends on how large your harddrive is, and how much stuff is on it.
After Malwarebytes has run, go to System Restore, and TURN IT OFF.
System Restore also keeps the virus files too!
[ Windows XP;
1) Click on Start.
2) Hover your mouse cursor on All Programs.
3) Go up to Accessories, over and down to System Tools, over and down to System Restore.
4) Click on System Restore.
5) In System Restore go to the left side/middle, and click on System Restore Settings.
In the System Properties window click on the small square, that is to the left of -> Turn off System Restore on all drives.
(Puts a green checkmark in the small square)
No go below to the right, and click on Apply. Then go below to the left, and click on OK.
Run Malwarebytes again. When finished go back to System Restore, and turn System Restore back on.
(Go back to the System Properties window, and click in the small square again. Removes the green checkmark. Click on Apply, and OK)
Now go to the System Restore window, and click on the small circle to the left of -> Create a restore point.
Click on Next at the bottom.
In the box under the purple(?) subheading ->
Restore point description, just type in a description you will remember.
Example? Restore point, and the date.
Then go to the bottom, and click on -> Create
For additional questions please post in a Comment.