I have an ACER laptop which came with Windows XP, which I have updated with all the current updates. This however keeps crashing mainly when using microsoft word but also with some other programs. Windows cannot figure out why it is happening and I have reinstalled the OS from the original disk 3 times, everytime with the same result- works well for a few weeks and then starts crashing. I have also had it checked by a computer expert and he could not find any problems.I have come to the conclusion that the original OS is defective and would like to know if I purchase a new copy of Windows XP OS will I have to also buy new copies of the other software like Office. In other words is the licence tied to the computer or the OS? Also is it possible to instal XP over XP?