System restore will have no effect, the infection will remain in the computer.
Please ask help from one of the malware team helpers in
http://forums.whatthetech.com/index.php? Follow the steps in the stickied topics THEN post your issue with description, and the logs that were requested at the stickied topics.
I urge you to do it ASAP due to the fact most of the forum users are focused on other boards, and
please do not take steps from ordinary users unless you have confidence in them. Remember, it can cost you!
Bad news; this type of infection is called 'scam-ware" and will usually ask money from you in order to unlock your PC, and this is obviously fake. Similar cause:
http://forums.whatthetech.com/index.php?showtopic=124824 (make your own topic if you wish, do not take steps from any other topic because it'll harm your computer because cases differ)
Good luck.