Is it the ram or cpu or something else that need to be changed?

It seem that changing the mother board was needed to confirm as there seems to be a problem related to non communication of the mother board with the CPU, RAM and sections.
Swap and confirm.

Try swapping out the RAM first since it's easier then changing out the CPU. If that doesn't work, then the probably most likely lies with the CPU.

Regards,

Matt

Try reseating the memory / booting with only 1 stick and NO battery just AC adapter.

What happens?

Try with the hard drive and optical drive out too if the above changes nothing.

Let me know what happens...

The minimum RAM required for XP is 128MB. You could upgrade the memory to 512MB or something. Under 512MB it will not work smooth.
The minimum required HDD is 1.5 GB. You have 4 GB. It is not that much, but it'll work.

The minimum required CPU is 300MHz. If your CPU is less than that, it'll not work.

I personaly would not recommend to upgrade to XP, the laptop may become very slow. i would advise to try it, and if it is not working smooth, then rollback to 98.

If you would like something newer than 98, I would recommend 2000.

Probably there must be loose contact of cables inside your CPU
Open the CPU cover and blow air to remove dust.
Unplug the Cables and re-plug ( Hard disk, CD ROM, )
Remove the RAM and wipe the RAM contacts and connect back.
all the Cables that connect the SMPS box (Fax box [ Electrical supply box)
check the cable connectivity on the outer side of CPU from PC sockets to Walljack..
this should normally let the PC boot.

u need to change graphic card first in something better !!!
what games u want to play, tell me and I'll tell u what u need exactly !
Your RAM ??? It can't be 2.6G, but that is place to start, ram must be same brand and value, compatible with Your motherboard !

Please check with hp if they can allow you to do that ...Incase if you end up doing this you might not able to get your system up and running ...as you are goiing to change the system board,graphic card
and if you want to increase the speed for pc upgrade your RAM and check with manuals how much Ram do they support
Apartfrom that increasing the graphic card is good option but do check nowa days nvidia is offering built in RAM on graphic card

hmm if it not beeping it means that is something wrong with the Ram memory ..check if its right inserted ...and is it is ...remove the bios battery , to reset it ..and reboot...you might have to reinstall cause sometimes when everything appears to be ok .but get blank screen its cause you messed up with the video card driver ...or collor setings...reinstalling will fix the problem if its from there ..but cause its not beep-ing at boot means its not recognizing the RAM memory ...
So ..the cause may be multiple ...either you changed the frequency of the memory ..and its out of its range ...or you have made changes on the memory configuration ...( changed ram or added more...) and in this case its just making a little click like its booting in looping ...if the memory its still working ...removing the battery for a few moments and restarting will get the bios on the default optimal factory settings ..and it will take the memory frequency at automatic values ....Good luck !

The 3 beep POST error code usually means there is RAM failure.
Reseat the RAM, if this doesn't work try one RAM module at a time.
The RAM may be incompatible and try and use RAM from the same make and speed.

Lorna,
to change bus to 133 MHz, you need to unlock the speed by setting a corresponding jumper on the board to assign busspeed by bios. After doing so, you need to clear CMOS and reboot. Next you'll have to set speed and multiplier in bios. Ideally: 900MHz = 100 x 9. Alternatively: 133 x 6.5 If that doesn't help...check if your RAM-modules are any good anymore. When RAM is not functioning, CPU-error code may be presented, since CPU cannot read/write to RAM, therefore not function. Let me know how this turns out.
Kind regards,
Stephan