Noob having trouble with blender (vga probs )

Hya peeps I m pretty new with blender but have the following problem:
Blender worked fine for a few months on my machine but yesterday I booted comp and wanted to start with blender and it was in black and white?! I have a fx 5600 vga card (128 mb) 1 gig ram 2600 athlon xp processor but didn t change anything recently … does anyone regocnize this problem or and can help me out?
I hope so thx in advance,