I am facing problem.when ever I come online a web page automatically open with name of system doctor.I think it's a spyware and I don't know how to remove it.

Does it go to the System Doctor homepage? If so you can go to "Tools" and "Options", then change the homepage from there. If it was spyware, then most likely, your computer would have many internet windows popping up, or a constant "Spyware Detected" on your desktop. Another sign of spyware is possibly files downloaded to your computer without your consent. If other things are going wrong I would suggest downloading AVG Anti-Virus (http://www.download.com/3000-2239_4-10741647.html), Spybot Search and Destroy 1.5 (http://www.download.com/Spybot-Search-Destroy/3000-8022_4-10743107.html?tag=lst-0-1), McAfee Site Advisor (Firefox) (http://www.download.com/McAfee-SiteAdvisor-for-Firefox/3000-11745_4-10663377.html), or McAfee Site Advisor (Internet Explorer) (http://www.download.com/McAfee-SiteAdvisor-for-Internet-Explorer/3000-2144_4-10663376.html). An optional piece of software that I recommend would be Microsoft Windows Defender (http://www.download.com/Microsoft-Windows-Defender/3000-12771_4-10598014.html?tag=lst-0-1).