Computer Randomly Reboots

[MaxPow3r]

About a week or two ago my computer started randomly rebooting while in Windows and sometimes would do the post beep an infinite number of times and never boot up. I ran memtest and discovered errors, so I reset my memory settings back to the default settings and ran memtest again. It made it through without any errors for about 30 minutes, then my whole computer just locked up. Now my computer continues to randomly reboot. My computer is 3-4 years old now and have never had a problem with it up until a few weeks ago. I checked the CPU and MB temps, they're the same as they've always been. I glanced at my MB and PSU and didn't notice any bad capacitors. Any ideas?

Here's the specs:
AMD Athlon XP 1800+ (stock cooling)
ASUS A7V266-E
512 MB Corsair Value RAM
GeForce 2 GTS Video Card
NEC 3520A DVD-RW
Yamaha 24x CDRW
Maxtor 15 GB 5400 rpm
Maxtor 160 GB 7200 rpm
Enermax 350 Watt PSU

 

[Blain]

Originally posted by: MaxPow3r
Here's the specs:
AMD Athlon XP 1800+ (stock cooling)
ASUS A7V266-E
512 MB Corsair Value RAM
GeForce 2 GTS Video Card
Enermax 350 Watt PSU

No hard drives or optical drives?

 

[EmoshBZ]

I had a buddy with a similar problem. Turned out that he had a faulty power spupply. Ram could be an issue as well.

 

[Trizik]

Bad power supply was also my problem in my newly built system. Same symptoms.