Never use system restore to try getting rid of a virus, it doesn`t work and can make things worse, a lot of viruses hide in system restore.
If Essentials isn`t finding anything, you really do need to download another program, try Malwarebytes free version, it can find things that Essentials doesn`t.
Download, update it and run a quick scan, choose to remove all selected when the scan finishes, then run a full scan and do the same.
If this doesn`t clear it add additional info to your question and state name of your computer.
EDIT.
As already said, if the virus won`t let you download try safe mode with networking.
I`ve just googled the virus though, and it might be pretty hard to get rid of.
If it was my computer I would boot into safe mode and copy any files I needed to keep, to cd/memory card/external, and restore to factory settings.
This would get rid of any viruses and have your computer running like new.