The big problem was trying to get the machine to respond. I knew from the avira log that the bug had been found on the 3rd so I tried to do a system restore to a date before that.By booting into safe mode I managed to get it back to a system checkpoint before the infection and then I had avira rescan the whole system.It found the bug again and removed it.I downloaded tools onto a stick from another computer and then installed them on the machine I also used another anti malware tool to scan it again.I scannned it in safe mode and again when I rebooted it in normal mode.
If you ever have this problem there are a number of topics to read if you search for "cannot access control panel or system restore".I am not an it professional so I was just following the advice from the various websites to remove this virus.
There is not a lot of info about the actual bug but I think that it was a rootkit.Some of them are getting very nasty and stop you even running the anti malware tools.