My laptop was infected with the Trojan:Win32/Weelsof.E, please check on Microsoft for the description:
I was desperate as Windows started up with a blank window that blocked everything else and I really didn't want to format everything and install my Windows/Ubuntu partitions again.
I copied some antivirus software on my usb driver and started windows in safe mode (F8) I've downloaded a copy of Kaspersky Antivirus Removal Tool then I backed up everything and launched the removal tool while in safe mode.
The Kaspersky Removal Tool is not a permanent protection but it will clean up your computer from all virus and malware!
It detected and removed the Trojan:Win32/Weelsof.E sucessfully and now I'm writing you from my IBM T42 with the cleaned Windows XP.