I've tried to install some games on my primary master. Medal of Honor and Grand theft auto took almost 30 minutes to install !! In general whenever something is written to my primary hd it takes a lot longer than the usual. I suspect there's something wrong with WinXP, i never had this problem before :\. I tried defragging but no resuts ...
If you look in device manager and expand the IDE\ATAPI controllers tab you should see a primary and secondary IDE channel. Open the properties for the primary channel, look in the advanced settings tab and make sure DMA if available is selected. If it currently set to PIO only it could be the cause of your problem.