|The red screen is not part of a new Windows 7 installation on a Toshiba laptop so I've no idea what CD/DVD you used to try and re-install Windows 7 with. Windows 7 does not have any red screens and it doesn't have a "Grub4DOS" menu, so it appears you may have used the wrong discs.|
To re-install Windows 7 as it was when the laptop was new, follow the instructions under the heading "System Recovery from Hard Disk Drive" here:
If that doesn't work, you can do it using the Recovery Discs which you should have made when the laptop was working okay. Boot your laptop from Recovery Disc #1 and follow the on-screen instructions.
The final option, if you didn't make any Recovery Discs, is to order them from Toshiba. If you live in the UK/Europe you can order them online here:
The discs will cost you approximately £35 UK Sterling.
Finally, when you've got Windows 7 re-installed and working again, the first thing to do is install a good & reliable antivirus software like Norton AntiVirus. You shouldn't get a virus infection if you're using good antivirus software.