|Assuming the system still starts up and lets you into Windows, I would suggest stopping all startup programs manually, restarting the computer, and then running a virus/malware scan.|
First, startup the system and log into your account. Once the account is logged into, go to start and select "run." Once in run, type "msconfig" and hit enter. This will bring up a Windows configuration window. At the top of the window, select the "Startup" tab. Once in the startup menu, click "disable all" and press "ok." Once the window closes, a dialog box will appear asking if you want to restart. Select "yes" and let the machine restart.
Once the machine is restarted, log in and run a virus/malware scan. If you don't have an antivirus and/or anti-malware program on your machine, I would suggest downloading avg free and spybot S&D.
Once the infections are removed, go back to the startup section of msconfig and click "enable all" and click "ok." Once the dialog box asks to restart, click yes. When the machine starts back up, everything should be back to normal.
I hope this works for you and best of luck!