Hey, I just upgrade my system to this:

Athlon xp 1800+
k7s5a pro

First it started fine, however I realize that the cpu was only running at 1.15GHz. So I change the CPU Speed from 100/100MHz to 133/133MHz and for a few times ran ok at 1.53GHz... But now, it wont boot, i had to clear CMOS in order to reboot it. And now, even at 100/100, it sometimes takes me 2-3 tries to boot it...

Any ideas?
Thanks

Weird. Good luck. I would take a lot in CMOS and see what temperature your system is running at just in case. Probably not the problem, but it sure wouldn't hurt to take a look.

This happened to me a year ago and never figured out what caused it I just ran that computer at the lower speed I will say that I did update the Bios and it didnt help and later I updated memory and video each time after I could never get it to run in 133/133 Im no computer wiz but it must have been in the Motherboard

Welcome to TechSpot forums

I've had a quick look at the ECS forums over at www.amdforums.com
A lot of problems seem to have suggestions of using only one stick of ram. You could try that (if your running multiple sticks) and see if that resolves anything.
Posting complete system specs including PSU wattage and brand would help with any possible analysis of your problem

Seems to be a few wrong speed problems with these models:
Duron 700 showing incorrect speed (466 MHz)

Found a link in a post there to a K7S5A problem fix guide
This includes a section on 133/133 problems here

I suggest you try these possible fixes if you have access to alternative pieces of hardware to try with it.