PC detects only 512MB RAM

Hello, so basically I'm in trouble as I'm working for a company administrating/moderating their site and products etc. and in our second shop/store there's a PC that is probs like 412093781029381029381029 years old and for some odd reason it's case etc. is used for servers not for PCs but whatever that's not the case here.

Erm so the problem is that the PC is working like proper **** after an unknown to me moment - idk what happened, I'm not and I wasn't using that PC as I work somewhere else, my friends (WOMEN - so yeah they have no idea what happened or what they did), opening Mozilla takes like 2 minutes or more, loading through the sites also takes loads of time, having 1 app running in the background then launching firefox makes the PC run slower than a snail, I've used Malwarebytes - removed all the crap, used CCleaner - removed all the crap aswell but still didn't help at all. I've checked all I could (I think, I'm not a specialist whatsoever, but just used common sense). At first I realised that there's only 256MB RAM so my first thoughts were:

1. PC is like 10 years old or even more so yeah probs running out of life (idk if that actually makes sense that if its older then it will run slower etc.)
2. Needs more RAM coz 256MB is way too low.
3. PC might've been dusted etc. but that's not the case.

Okay so I've opened the case and saw 2 RAM chips in there, apparently both of these are 512MBs, so automatically that makes no sense that there are 2x 512s and PC detects 256MB only. Both of them were inserted properly so that's not the case but when launching the PC there was an alert that the memory is limited to 256MB so had to turn that off in BIOS although that made PC detect only 512MB even though there are 2 chips of 512MB. So yeah maybe the chips are from different companies/have different values etc and may mismatch or something. I've used a specific site that automatically looks for a proper RAM for specific PC and I've bought 1 chip of 1GB and inserted it into the case and still nothing happened - didn't detect more than 512MB anyways. I'm no expert in these cases so I've asked my friend to take screenshots of CPU-ID/CPU-Z (screenshots and she took photos with her phone xD) and I'll just post them here for you guys so you might be able to break down what's wrong, if the memory is mismatched and what should I try/do. Btw. for some strange reason I can't get into BIOS (they use wireless keyboard+mouse but I took my wired keyboard that works on my PC and for some reason I still can't get into bios by F2ing).

Here are the screenshots - sorry for the **** quality (imgur album):
http://imgur.com/a/DFXpM

Oh and by the way when I'm launching the PC it says "Memory mismatch, DIMM1 and DIMM3 (not quite sure which one, either DIMM2 or DIMM3, can't remember), Please populate memory in pairs" - something like that, I haven't been there for like 2 weeks so I don't remember everything, sorry.

OS:
Windows XP 32bit SP3

I would appreciate any help.

 

Number one problem, it's still running XP, and that's simply asking for it.
Though the machine is a Xeon (server processor), it's still a :*** dinosaur.

If you haven't fully reseated the DIMMs or swapped them, do so. Make sure the slots are dust free. Usually, channels 1 and 3 are a pair, and 2 and 4 are a pair and modules should be identical. Occasionally such is not the case, and they will be 1 and 2, 3 and 4, but they should be color coded as far as matching purposes. Additionally, your 1GB module is slower than the other two which can cause issues. You may not have a choice but to install them in pairs if dual channel is enabled.

There could be issues with the DIMM module itself, or possibly the motherboard.

The issue could also be that the CMOS battery requires changing. A fresh CR2032 has been known to work wonders.

A Speccy report on the machine would be useful.

 

Yeah I know that this thing is old af LMAO
To be honest with you I have no idea what a "DIMM", as I've stated before I'm crap at tech things inside PC so yeah and I'm also not a native english speaker so my english is pretty bad which means if you'd explain that in the easiest way to understand then I might understand it haha, sorry :/. So basically as far as I remember the 2 512MBs were next to each other in the slots, so what you mean is to reseat the 2nd one into 3rd slot in order for it to be working in pair? If that wouldn't work can I just remove 2 of them and put 1GB stick into 1st slot and that should do the job? Btw. I have no idea how to enable/disable dual-channel and I've got no idea what it is, all I do is read through internet and try it out by myself but I'd rather ask experts than do a YOLO style lol

 

From Dell: 256MB non-ECC DDR266 SDRAM standard; 4 DIMM slots; 2GB maximum: 128MB DIMM (ECC or non- ECC), 256MB DIMM (ECC or non- ECC), 512MB DIMM (ECC or non- ECC), 1GB DIMM (non-ECC only).

Memory module connectors must be upgraded in matched pairs. Memory module
connectors 1 and 2 must contain modules of identical size, type, speed, and number of
chips and memory module connectors 3 and 4 must contain modules of identical size,
type, speed, and number of chips. To locate the memory sockets on the system board,
see the system board components illustration (for the Dell Precision 450 computer, see
"System Board Components" or for the Dell Precision 650 computer, see "System
Board Components") or the system board label inside your computer.
• Before you install new memory modules, download the most recent BIOS for your
computer from the Dell Support website at support.dell.com.
Your computer supports a maximum of 4GB of memory when using four 1-GB DIMMs.
Current operating systems, such as Microsoft® Windows® 2000 and Windows XP, can only
utilize a maximum of 4 GB of address space;
Crucial replacements: http://www.crucial.com/usa/en/compatible-upgrade-for/Dell/precision-workstation-650
Crucial states: Maximum memory: 4096MB Slots:4 (2 banks of 2),
So you need to have pairs.
Dell says 4 slots -2GB Max = 8Gb, who's right?

Plus the BIOS is old, check http://www.dell.com/support/home/us/en/04/product-support/product/precision-650/drivers
Dell's Memory Troubleshooting: http://www.dell.com/support/article/us/en/19/SLN284238/en

 

Crucial shows non-ECC for RAM upgrades.

http://www.crucial.com/usa/en/compatible-upgrade-for/Dell/precision-workstation-650

Make sure that your RAM sticks (DIMMs) match, and are in the matching colored slots. IF they are all black then move the pair of sticks to the opposite pair of slots (3 and 4), and note any change. Your 1GB stick will not work according to Dell and Crucial's recommendations. Xeon processors will support either error correcting (ECC) or non-error correcting (non-ECC) RAM. However it does not appear this motherboard can accept ECC RAM in sizes larger than 512MB.

If you can no longer access the BIOS, it could be an issue with the motherboard itself. Without running PCDoctor and testing things like the EEPROM which stores the BIOS it's hard to condemn the board from the symptoms you describe.

Flashing the BIOS is usually a last resort but pulling the CMOS battery (the little watch battery) and resetting the BIOS is a good place to start.

If you are savvy enough, you could create a bootable version of MemTest on a CD-ROM and test the RAM.

http://www.majorgeeks.com/files/details/memtest86.html

Use the first link, which is an .iso file that can be burned to a CD and is bootable. Any red is bad...