No. Try it if you want, as you can run some 125w cpus. The phenom I is listed in the update list. If you can't afford a decent power supply, then you shouldn't upgrade just yet. Your original power supply is probably 250-300 watts. For a new ps, look at antec, corsair, seasonic, or enermax in 500-600 watts. For the board, msi makes the 785GT-E63 for $85 that works with ddr2 and will run the phenom 955 with a bios update. I've found remarkable deals on craigslist, if you have it available in your area. Right now a trader is selling his gigabyte board with 4 gb of ddr2 and 710 tri core cpu for $85; would probably take $70-75. You must use a micro atx board for your hp case. And a non hp board normally requires a new windows coa. Your original windows operating system is designed to work only with hp motherboards.