i think you have a nasty in your system. please try to scan with malwarebyte's anti malware. here is what you'll do

1. - Download Malwarebytes' Anti-Malware (http://www.download.com/Malwarebytes...=dl&tag=button) to your desktop.

* Double-click mbam-setup.exe and follow the prompts to install the program.
* At the end, be sure to checkmark the Update Malwarebytes' Anti-Malware and Launch Malwarebytes' Anti-Malware, then click Finish.
* If an update is found, it will download and install the latest version.
* Once the program has loaded, select Perform full scan, then click Scan.
* When the scan is complete, click OK, then Show Results to view the results.
* Be sure that everything is checked, and click Remove Selected.
* When completed, a log will open in Notepad.
* Post the log back here.

Make sure that you restart the computer.

The log can also be found here:
C:\Documents and Settings\Username\Application Data\Malwarebytes\Malwarebytes' Anti-Malware\Logs\log-date.txt
Or at C:\Program Files\Malwarebytes' Anti-Malware\Logs\log-date.txt

2. - Download hijackthis and post the log.

In your reply, post the logs (in this order):
1. - Malware Bytes Log
2. - Hijackthis Log


if it's a virus attack, then your post will be redirected to the viruses and other nasties forum.
anyway i hope your problem get's resolved quickly.