Hi ! At present I am using XP pro and I want to re-install windows 2000 but when I tried to I got the following error message displayed on screen : Disk I/O Error = 0003200 and after a second or two this message is displayed : File acpi.sys caused an unexpected error (12800) at line 4244 in F:\nt\private\ntos\boot\setup\setup.c And F Drive is my CD-RW and I am booting my cd from E: I am really in need of help. Please help me out ! Thanx in advance Sandeep Arora.

WHY DON'T YOU BACKUP YOUR DATA,then make a clean installation of win2000

Are you running W2K setup from a CD boot or via the 4 floppies + CD; i.e. not from within XP? Incidentally why the wish to revert to W2K? I note you seem to have only 128Meg RAM installed? If this is so them I doubt XP really managed to work anywhere near reasonably... W2K will (just) be OK with 128Meg, more would be beter... A clean install would be wiser - if that's a viable option. You would logically back up all data first; also ensure you have all required drivers for W2K.

Thanks for your response ! I am running win2k from a cd boot without using any floppy disk. One of the solution that came to my mind is that if I remove my F: and then try to install the OS, will that work ? and after installing win2k I will re-install the F: What do you say ? Would it cause any further problem ? regards.

Is there any reason to suspect the F drive? The I/O error is likely related to the HD. I'd just wipe the drive and start fresh. M2 If at first you don't succeed, you're about average.

I tend to echo M2... If you really wish to lose XP and revert to W2K (only) - start afresh. Backup all data etc.; ensure you have all required W2K drivers etc. Then reformat/re-install... (Ideally reconfigure drive to have both Primary and Extended partitions - Primary for OS/apps/utils; Extended for data only?)