|A virus can not do that. (almost zero chance)|
Either your cd is bad, your cd reader can't read the Windows 7 DVD (dvd?) or you are not seeing the press any key to boot from dvd.
Most laptops can be returned to the original state. See owners manual for how to do that.
1/3 of highway deaths are caused by drunks. The rest are by people who can't drive any better than a drunk.