Laptop hangs with HP logo when i press start button.?

to trouble shoot it you need a os on a cdrom but to start, try to boot into the safe mode and see if you can do that. set it back to a date before you had this problem try this website a href="http://www.microsoft.com/security/scanner/en-us/default.aspx" rel="nofollow"http://www.microsoft.com/security/scanne…/a this scanner may be able to help you.