It looks like you have a malware problem.
Try booting into Safe Mode.
If that does not help
When at desktop press CTRL + ALT + DEL to open Task Manager
File/New Task (Run) and type in
Does this bring back your Start Menu?
If you can access the system now you will have to get the infection cleaned out
Please read this article… "Having problems with spyware and pop-ups? - First Steps"
; follow the instructions very carefully; then, post all the requested logs and information; as instructed, in the HiJackThis Log Help Forum
Please ensure that you create a new thread in the HiJackThis Log Help Forum; not back here in this one.
(Please change the new Thread Subscription to “Instant Email Notification” so that you receive an email as soon as a reply is posted,)
When carrying out The 5 Steps, if you cannot complete any of them for whatever reason, just continue on with the next one until they are all completed.
However,it is extremely important to make mention of the fact that you could not complete any of the steps in your post to The HJT Help Forum; where an Analyst will assist you with other workarounds.
Once done, please be patient, as the Security Team Analysts are usually very busy; one of them will answer your request as soon as they can.