Firstly roll bk to your last system restore point and see if it works.this gives you a window to narrow down the problem. If no joy then Try updating your software /drivers as sometimes old ones become obsolete causing loading problems. Also do a full malware scan.
try starting in safe mode with command prompt( hit f8 upon booting up) type explorer in the command prompt and use system restore to the closest point (system restore cannot be undone in safe mode.)then either download a reliable malware disinfecting programme or run the one on your system as I think the white screen is a nasty Trojan that needs to be removed.