I got this computer about 3 years ago and it was pretty simple. So I upgraded LATER on with some Ram, so instead of 512mb I have now 2.5gigs.

Recently I was thinking to upgrade my memory again, to add an ADDITIONAL gig, unfortunately I found out that because my 512mb ram runs at 533Mhz the other 2 gigs won't run at 800mhz like they are supposed nor will the new 1gig memory run at the speed it supposed to.

So I tried to remove the 512mb Ram, that was originally in the machine, but the computer won't boot any OS, it just makes the pipping constantly, it's a long pip, for about 30 seconds or so then stops and then starts again.

I went to Dell and tried to upgrade the Ram and what they giving me is basically the same options for my exact computer, I did the analyze. So they are just showing me the 800mhz ram but if I upgrade it, it won't run at 800mhz because of the 512 Ram. Get it? Let me know if there isn't enough info, I can try to give you more, just not sure what else to give.
Thanks in advance.What OS is it? 32-bit, or 64-bit?
Check here: http://www.crucial.com/store/listparts.aspx?model=Dimension%20C521 for correct type of RAM, and correct way to install it.it's 32 bit windows 7, XP, and ubuntu.Did you check my link?Nope...That was a rhetoric question I did, I've been there before I went to these forums, that's where I was PLANNING to upgrade my memory. My question was, why is it that my computer can run all the memory downgrading it to 533MHZ but it can't run the memory without the 533Mhz that downgrades my 800Mhz, not what kind of memory I need lol. And if my computer can't handle the 800 Mhz then why all upgrades with 800 Mhz? that's like a waste of Mhz ya know lol.
Anyway, here is my DxDiag, so may be that might help out to answer the question.

Operating System: Windows 7 Ultimate 32-bit (6.1, Build 7100) (7100.winmain_win7rc.090421-1700)
Language: English (Regional Setting: English)
System Manufacturer: Dell Inc
System Model: Dimension C521
BIOS: )Phoenix - Award WorkstationBIOS v6.00PG
Processor: AMD Sempron(tm) Processor 3400+, ~1.8GHz
Memory: 2560MB RAM
Available OS Memory: 2558MB RAM
Page File: 789MB used, 4326MB available
DirectX Version: DirectX 11
DxDiag Version: 6.01.7100.0000 32bit Unicode
Card name: NVIDIA GeForce 8600 GT
Manufacturer: NVIDIA
Chip type: GeForce 8600 GT
Display Memory: 1525 MB
Dedicated Memory: 501 MB
Shared Memory: 1023 MB
Current Mode: 1280 x 1024 (32 bit) (60Hz)

I think that's all the info you need to know, if there is something else, please tell me. Thanks.One more time. Did you go to my link, and did you check, if you have correct type of RAM?YES, I did. It is a correct type, did I not say that already?