I have a computer for one of my client , I tried to install Microsoft office 2003 and it give me error message 1335……..I though problem with my CD, then I used different CD same error message. After spending hours to solve this issue I could not , I tried many all of them did not help me out. Then I formatted hard drive and I installed fresh copy of windows XP SP2, every thing going fine. Now I tried to install office again same problem , then I tried to use adobe Photoshop CD same error message 1335 , then I tried to install SP3 same error message 1335. Now I have been convinced that the problem with the western digital hard disk ( WD800JB) IDE not SATA, I downloaded utility for WD to test (short and extended) the hard disk the result shows me there is no error. What could be causing this problem ? Why installation went smoothly while installing programs did not ? if the CD Rom (SATA not IDE) would have causing this problem why not with windows CD ?