GeoffW1,
Here is a link (safe) to probably the best info on Cryptovirus from bleeping computer:
http://www.bleepingcomputer.com/viru...re-information
Here is another link (safe) for the free software (referred to in the above article) that will prevent the Cryptovirus:
http://www.fooli****.com/vb6-projects/cryptoprevent/
For those who don't know, this virus will encrypt your files, then demand a ransom ($100 to $300) to get a key to de-encrypt them. They give you 96 hours or the files will remain encrypted permanently. No current virus protection program appears able to block it.
Hope this helps,
Jim