I have a 4 year old PowerBook G4 running a 1.33 Ghz processor with 2GB DDR SDRAM installed on a 50GB HD. I usually have OfficeWord and OfficeExcell open along with Safari, Mail and the Address Book. I close other applications after their momentary use. All of this worked great with Tiger, but when I upgraded to Leopard it became a crawling cat. I am plagued with frequent spinning color wheels of death. These lead to the application failing or simply taking a long time (several minutes) to resolve and give me back my computer. I have defragmented the HD several times and this improves things, but it's still "iffy." I have about 15GB free on the HD. My questions are: 1. If I upgraded the HD to a 100GB (or larger) would this eliminate the problem. 2. What HD (brand, size, etc.) should I install? Thanks a zillion!