Dear SIR, I have using 3 PCs. one is at my Home and the other 2 are at my office. I usually down load or create some files or programs or software and simply write the same into a DVD(frontech) using my HOme PC DVD writer and get the DVD to my office and down load or copy them into the 2 PCs. And, I usually write multiple times into the DVD disk. Yesterday, I copied files another time from time my Home PC and tried to read from 1 PC of my office. Suddenly, I exclaimed that, the DVD is showing No matter in the DVD disk and the auto play asking to create a new data DVD or music DVD. Then, I immediately tried the DVD to read in the other Office PC. The all the files are visible and avail to accessible to me. More over, the DVD again gave same trouble to me on my Home PC. Today, I again tried to open on 3 PCs and got same results one PC is able to read and the other 2 PCs are failed to read and the auto play asking to create new DVD. I particularly, can tell that the 3 systems' DVD writers are having same Anti-Virus software but OS is different. At my home, Windows 7 ultimate and at my office in 2 PCs Windows XP professional OS is using. I am feeling very inconvenience with this problem. Is there any mistakes would taken by me. And, the PCs at my office are working with PEN Drives Hence, PLEASE ADVISE ME TO OPERATE THE SAME DVD disk ON ALL THE COMPYUTERS. Yours sincerely, bitras