I don't think it's necessarily your system, though you are really pushing things. I have a P4 2.4 1gig of ram and lots of disk running in XP pro and I am the Admin. Bryce is not fully up to date to run on windows. You can quit while it's still saving and windows won't stop you like it will with office programs. It's unfortunate, but it happens even with big systems. Call it cosmic rays, Hitting a key while saving, whatever. Just remember Save, save, save. I Agree with your idea about Burning CDs. I put my work and even copies of my models in the same working folder. When I'm done I burn the whole folder with the multiple saves to a CD. (I wait till a stack is on sale and buy 100 at a time. It usually only costs 30 cents to back everything up.) I make two seperate copys then delete the folder after I open both files from the CDs to see if they still work.