That power supply is ancient, the -5 V rail and the low 12 V rail current limit are give aways. The 8 amp limit on the 12 V rail means you have only 96 W for the CPU, GPU, and fans which likely isn't enough for a P4 system. The lowest power 2.8 GHz P4 chip requires 68 W for itself, some need up to 89 W.
Really, that PSU is an ancient POS, get yourself a modern unit with good power distribution. A Corsair 430CX is more than enough for that system and is fairly inexpensive.http://www.newegg.com/Product/Product.aspx?Item=N82E16817139026&Tpk=430cx