I just upgrades my system to Athlon 1900+ K7S5A Pro 250W PSU 512mb DDR 2100 CDRW and DVD 60G + 100G Western Digital Hard Drive. it's running so slow, won't do s---. Any reason why? could it be PSU is not supplying not enough Power?

I found out, definately PSU problem. i boot it without CD-RW and DVD, took 55 seconds to boot. (Average time for booting? or is this kind of slow?) with CD-RW and DVD connected 3m or more to boot, plus so much lag. i'm thinking about getting 400W or more PSU, I don't think my MOBO likes GENERIC mobo, what are the major brands for PSU? Any good recommandation for PSU which is compatible with K7S5A Pro mobo. if u can provide link and price it will be great help, thanks for reading. Also anyone have link to CPUIDLE hacked version which doesn't required to purchase it or register?

I know I'm not johnoh, but your problem is caused by your PSU. 2 hard drives, 2 optical drives plus an Athlon XP processor running on 250 watts is not a good idea at all. You really should get that 400w PS. Good brands for PSUs are like Enermax, Antec. 55 seconds of booting time is quite slow. Mine (2.8 GHz, 1 GB) only takes 15 secs to boot, and that's with 12 mini-apps running and 80 processes running. The PSU upgrade should help you out greatly.

Definetly go for a 400w PSU. YOu could get by with a 350W, but its better to have more power, am i right??

Yes more power is better!...I recommend Antec's power supplys!!...They are powerfull and quiet!!...I had an HP Pavilion xg838 and it had a 800Mhz Celeron with 256 RAM and 1 HD 1 CD-ROM, the stock HP had a 100W PS. :(. Then i upgraded the case to an Antec SX1035 SOHO File Server Tower Case and it has an 350W Antec Smart Power Supply, and my old Celeron bosted some power!!...my boot times decresed and some of the lag in games took off!!!.... The Smart PS is not the best one from antec, but its still is good! the 550W True power is the best one fromm antec!! :) www.antec-inc.com