go to Internet Options>click on the Security Tab>click on the Internet Globe picture (if not selected) and click default>after that, click apply. then click the the Advanced Tab on Internet Options>and click RESTORE DEFAULT>click ok
if that don't work, u can try to disable ur firewall and try to go to a secure website.
if that doesn't work, then reinstall ur operating system. u don't have to buy another operating system cuz u already got it. it cums wid ur computer when u bought it. look for it
Intel Core 2 Quad Q9550 2.83Ghz || 4GB OCZ 1066 DDR2 RAM || GIGABYTE GA-EP45-UD3P Motherboard ||
PNY XLR8 GTX 470 || Raptor 300GB 10,000 RPM HDD RAID0 || Windows 7 Professional 64-bit