Met Police Virus (unable to acces safe mode)

Hello,

Windows XP

Had just got myself one of those Met Police Viruses, i belive they are called ransomware.

On google the general concensus is to get the PC into safe mode, then you can do system restore etc. etc.

Dunno if i have got an updated version of this virus but NO "safe mode" option works for me !

* I press f8, then yes, it gives me the options of Safe Mode / Safe Mode with Networking / Safe mode with Command Prompt etc, yet....

When i press enter on ANY of these options, black screen, then lines of writing scroll up the screen, then screen goes white for a second, then once again returns to the screen above, giving me the "safe mode" options as before (*) :cry

If i choose "Start PC at a point in the past when it was known to be working"... Bingo, same Met Police Virus Screen.

What can i do ?

Many Thanks...

John