i get similar errors every 3rd or 4th time i run nlite, the file in the message changes each time. Vista sp1 x64 here, with .net 3.5 installed. it might be unrelated, but booogy's wmp11 slipstreamer hits a wall quite often as well. The source isn't hosed after it, as nothing had been modified yet, so i just exit and run the program again until i get a success. both the nlite and wmp11 slipstreamer issues occur regardless of whether i'm using xp, server 2k3, or xp x64 as my source. never had this problem before installing sp1. Perhaps a problem with .net?