It is my impression that desktop rebuilds do depend upon the hard drive size and especially the number of files on the hard drive. I expect that your iBook has a much larger HD, with a lot more files that must be scanned, than your old system did. The System folder (not System Folder) for OS X has thousands of files--mine has over 30,000 items (files & folders), and I don't actually USE OS X, yet. George Slusher/Eugene, OR gslusher at rio.com