PLEASE HELP- DESPARATE

Thank you in advance, My fiance has a huge problem with her Toshiba Lap-Top. She is running Windows XP and every time she tries to log on all she gets is the background of her wallpaper. No icons, no log-in screen, no error message, nothing. She did start the computer in safe mode and ran CWShredder, Computer carp** Cleaner, Adware, Norton Anti-virus, and computer Defragmenter. She had a few items to clear with Adware, but other than that, nothing. She is in medical school and has a very big presentation coming up and really needs use of her cpu. Any help or suggestions would be much appreciated. She is breaking down and I'm going to need to come up with something soon. Thanks C

The plot thickens: Now my fiancee states that she was trying to Download Panda's antivirus program yesterday. She found a log on her cpu which states that she started to run the program, but it failed to install successfully. I know that Panda and Norton are incompatible. Now her Norton scan will not work. Any chance that she did something by trying to install the Panda that is now keeping her from logging-in. Also, their is no option to uninstall panda in safe mode. Any help? Thanks, C