If everything is connected as it should be then its possible that vital files to run your system in a stable manner may have been damaged or removed, or what infected your system was meant to restart your system constantly in this annoying way. your best bet now may be installing the hard disc onto another pc (thats fully anti virus and trojan protected-make sure the hd is fully scanned before browsing or opening any files on another machine) to try and save any personal files that you may consider important. If theres nothing of importance and cannot get hold of another system then you could always just reformat your hard drive and reinstall windows. if your system was up to date with virus protection and working firewall previously, and your cousin is no beginner, i wouldve been onto him to find out just what questionable websites he was browsing to or what he was downloading on my pc. you may still be able to find out of course if you can browse the same hard drive on another machine, checking out browsing and program history-best of luck.
Baidu is a china search engine, similar to google click here and just like google, according to the guardian, may link to often questionable websites. the chinese government wants to control it no doubt. I hope you get your computer sorted click here