SOLVED AMD Computer Problem please read

I have a problem which i can not figure out , i feel i am a experienced user when it comes to software and hardware for computers
specs
Gigabyte 7IX
128 pc 100
900mhz t-bird slot a
250 watt power supply

First off i just formatted my HDD last night and reinstalled windows 98 and my network card drivers and video card drivers and no sound card. I also loaded my cd rom driver
My problem happens radomly either when surfing the net or just running a video game. Ok what happens is it will just all of a sudden lock out on me and i dont understand it because my temps are fine 42 c running 900mhz t-bird slot a. another odd thing is when i press my power swtich on the case nothing happens. I kinda think i might need a new power supply since it is about 2 years old and its only 250watts. I am running 2 HDD's ,floppy , 2 Cd-roms and 2 fans "cpu and video card". Sometimes after the lock out i will have to go to my surge protector to shut it off or i could press the reset button to just reset it. I have reinstalled windows and formatted my HDD installing minimum drivers like 5 times with no difference. Sometimes another problem is when i logg on through dsl my modem wont be able find any web pages at all, and when i disconnect , i cant even reconnect. The only conclusion i could think of is either my power supply or some IRQ on my motherboard died and isnt fuctioning properly. I flashed the bios and still does the same thing. I also think it might my my voodoo 3 ? who knows. Right now i dissconnected 1 cdrom and my video card fan that i added.
Any ideas , i hate to have to upgrade to buy a different slot a motherboard .

That much stuff with a 250?
DSL modems normal needs to be turned off and on when the computer was powered off in a un-normal shut down. If you don't then it tend to not be able to locate the server on the other side. Meter the power and verify that the 5 and 12 Volts are ok. I have choked my chip before when my 5 V dipped. below 4.7

A Voodoo 3 shouldn't draw that much power, although a 300 (or greater) Watt PS would be HIGHLY reccommended. Have you been "playing" in your bios? If you change memory settings and the Ram isn't quite up to snuff it can cause your system to do some pretty strange stuff, and the power botton sounds like you've got soft-off enabled, that's why I bring up the question of the Bios. I have soft-off enabled on mine, it's a god send when you have a curious toddler running around the house! Also if you update your bios it can sometimes have adverse effects on your system. Check your bios, especially if you've changed some things, change them back and see what happens.

Thanks for the reply

I just bought a new powersupply after swapping out the video card, ram. Anyway thank god for comp usa return policy "14 days" I originally bought a 300watt PS "Comp USA brand which tottally sucked . "DO NOT BUY A GENERIC BRAND POWER SUPPLY.
I went back and bought a brand name called A-open 300watt PS. This power supply rocks. my orginial temps for my 250 would get as high as 50 C and system temps around 54 C on full load. Now my computer is tottaly stable and im running system temps as low as 31 C and cpu temps 38 C on full load. Right now running a crappy single fan on my slot A 900mhz but i plan on ordering a new high performance slot a fan rated for 1.2 gighertz. I ordered a GFD so i should be at 1000 easy next week. i bought my computer 15 months ago for like 450 bucks and then went from a classic 600 to a 900mhz t-bird for $125. i guess im going to order 2 sticks of pc 133 , 256 ram and eventually get either a ultra geforce or geforce 3. I just dont see the reason to upgrade to a socket A , DDR board. when the athlon 4 comes out and pc3200 and motherboards that take FULL advantage of DDR and yeah ill dish out 800 to 1000 bucks for a computer. but until then ill stay with my 900 old slot A and overclock it soon to 1000mhz. My computer woops the DURON 900 , I just dont see where its worth upgrading to a socket A right now if you own a slot A mainboard that can take 1000mhz