Malware be gone

One of your Windows 7 systems appears to be infected with malware that is causing a Windows STOP error (BSOD) just after login. Which of these troubleshooting tasks would be the best next step?

A) Replace the MBR using FDISK

B) Download a bootable CD/DVD to use with the computer

C) Start in Windows Safe mode and try logging in again

D) Update the anti-virus signatures

E) Try to locate the spark lighter for your welding torch