Task Manager Processes is full of instances of Consent.exe
Can't access Firefox Safe Mode in All Programmes.
Can't even switch off or on.
Cursor has a circle running beside it all the time.
In Task Manager plugin container is showing about ten times normal usage.

Stayed up most of the night trying to sort this out.
When I ran the cursor over the Microsoft Security Essentials icon it kept assuring me that my system was protected.
Quick scans assured me of the same thing each time.
Eventually I ran a full scan which took some hours and the results were startling from a programme that kept assuring me that I was protected.
the following items were found:
Exploit.Java/CVE-2010-0840.BV
Exploit.Java/CVE-/2010-0840.BJ
Exploit.Java//CVE-2010-0840.CR
TrojanDownloader.Java/OpenConnectionJ
All were removed.
System still wouldn't work.
After a long time I got into Safe Mode - by shutting down at from the on/off switch a few times.
Security Centre could not be started, nor could a Network Connection be found.
On restarting the machine in Normal Mode everything seems to be running well.

Can anyone tell me please if there is anything else I need to do.
All seems well at the moment, but I would appreciate any advice.
Thanks.

System seems to be working well, overall, now so
I will close this thread and mark it solved.