I have a Dell inspiron 1545 with Windows 7 Home Premium x64. I recently reinstalled AutoCAD 2012 Student Edition on my system (I had this installed earlier but I'd uninstalled some of its components). Since reinstalling, the Windows Logon screen takes around 3 minutes to appear after the Windows logo disappears after booting. The only thing on the screen is the cursor. Pressing ctrl + alt + del does nothing. I can only move the arrow cursor around for 3 minutes. Restoring the system to a point before I'd reinstalled AutoCAD fixes the problem, but reinstalling it brings the problem up again. How do I fix this??