almost immediate freezing of PC

Here it is again ........

Few things to check first:

Motherboard chipset drivers
Video Drivers
Memory settings
Power supply

Sounds to me like its starting to **** out when you put any kind of a load on the computer. Although socket 370's aren't power hogs, if you are running a 250 watt or less PS or an old PS, this would be a smart upgrdae regardless of whether or not its the root cause of your problem.

Now, we resolved that your processor is a 478 pin Celeron and you got some stability improvementwhen you went to optimum performance tab in the bios. Thats about all that you have done. I still believe you need to tweak your memory settings and feel that your PS is marginal. I can't and won't make any recommendations on memory settings without knowing what you have. 3-6-3 &T2 is relatively timid and Cas 2.5 is probably your default latency. You need the Via 4 in 1 drivers and I checked out your chipset before asking the question about your MB drivers because I didn't think you had installed them. You are probably also using the embedded default XP video drivers instead of the latest drivers for your video card.
Go here and do some reading:
http://www.rojakpot.com/default.aspx?location=1

Good Luck....

 

I've determined that there was probably not the memory DDR which has been causing an instant hanging up of my PC. I have replaced another DDR and the PC froze the same way it did before.

Maybe it is the old graphic card for which I have no updated drivers, because the RIVA 128/128 ZX is not supported on WinXP. The O/S installed it with its own drivers.

Can the graphic card cause the freezing? How can I determine this?

 

If your machine once ran fine and then you started having problems, that would be one issue - however, you have never run fine. Simply switching memory probably isn't going to tell you much, especially if your memory settings are incorrect. You need to focus your attention on BIOS settings and installation of the proper drivers. You may want to start by using the setup setting in your BIOS. As to your video drivers, the VIA 4 in 1 has to be installed first, followed by correct RIVA 128 drivers. Go to your video card mfg's website for the most recent XP drivers. The RIVA 128 you referenced is the NVidia chip on the video card but you need mfg specific drivers according to NVidia. Did you read the info in the link I sent - your answer to BIOS settings including memory will be found there, but you have to read it. My original suggestions included 4 things to check and you responded that you checked them out and nothing changed. Now, you keep coming back and one by one are saying that you haven't checked these out. I think my fingers are going to give it a rest.