One day i was carrying out a virus scan(Kaspersky) and chatting away on my messenger when suddenly everything hanged,explorer shut down and when it restarted i saw my scan was still runnig,but the 3d appearance of XP has changed to 2D.i cant get it back in any way now. infact none of the other user acoounts have that 3d effect in Xp. how do i get it back?i have an athlon xp 2000+ on an ASUS A7n266vm mobo with 256 mb ram.i'm runnig xp sp2.