Its probably virus related...
Open IE, click on 'Tools/Internet Options' in the menu bar and then in the 'General' tab under home page click on 'Use Blank(Do this if you are referring to the problem occurring only on startup)...Now...
Download Malwarebytes' Anti-Malware (MBA-M) to your Desktop.
* DoubleClick mbam-setup.exe and follow the prompts to install MBA-M.
* Be sure a checkmark is placed next to 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 MBA-M finishes, Notepad will open with the log. Please save it where you can find it easily.
* Immediately Reboot the computer..
Then Download
Trend Micro HijackThis 2.0.2
Install it and click on 'Run a scan and save the logfile'.
Provide the logfile of MBAM and Hijackthis Here.. 
Unsolved 
