|Try booting into Enable VGA mode.|
Instead of pressing F8 while booting until you see the boot choices menu and choosing Safe mode, choose Enable VGA mode.
That mode loads everything normal does, except it forces the video to use default VGA drivers instead of the specific drivers for the video chipset.
If you can log into that no problem, and you experience no problems, your problem is probably related to the specific video drivers you're loading.
By the way, you may not be able to un-install some software in Safe mode - you always can in Enable VGA mode.
If you can't log into that either, your problem is probably caused by another software problem