A virus is blocking my computer posing as Canadian intellegence services., as I am trying to enter safe mode with command prompt.
1 - If you have your Windows XP Installation Disk:
In Bios (f2) key - Change so CD is 1st boot device.
Boot from CD and repair install the OS.
2 - Create a bootable rescue CD.
From a working computer, go to Kapersky Site. http://support.kaspersky.com/faq/?qid=208282173
Create a rescue CD or USB to boot from for the infected computer.
Note: Downloading / burning and running the cleansing cycle will take some time to complete, but is very thorough and should get you going. If an update option appears during installation or cleansing, do it as the signature data base will probably have to be updated to include the latest infections.