desktop memory s4020wm presario?
450842
Appears to be DDR Ram PC2100 nonECC\n\nhttp://dealnews.com/memory/prices/systems/Compaq-Presario-s4020-wm-PC2100-DDR-266-MHz/32284/128MB.html
690703
Every motherboard has a part number, usually next to the serial number.  Copy it down, type it into Google, and it should come up with the specs of your MB including the type of memory required.
1130434
Go to www.crucial.com  (a memory manufacturer) and use their Memory Advisor Tool.    You select your computer's brand, model, etc.  and they tell you exactly what to order.\n\nThere are lots of different models, but there are subtle differences, so don't order anything just because it looks "close".    Although some of the "close" ones will work, sometimes small differences will make big differences in performance.  \n\nIt's better to spend a few extra bucks for something that is an exact match for your pc.    It will last a long time!
946856
Go to HP.com.On their support page you should be able to find the manual or a specs page. They will be listed by system model # or the model # of the motherboard. In either case it will give you the maximum amount of memory the system will take per memory slot. Also the memory speed. Be sure to pull the power plug before you change any internal component, especially memory. Good luck.
1177094
I think you answered your question without even realizing it.  You can install pc2700 ddr memory.  It is also known as DDR333.  The link is to Newegg, 512mb starts at $45 shipped.  Much cheaper than  Best Buy, Circuit City etc...\n\nSome people will tell you to only buy the expensive brands, but I have never noticed a problem with the lesser known brands.  Look for lots of reviews, it is usually a good indication of a well liked product.\n\nI would suggest checking to see if you computer will support 1gb (probably) and purchase that.  512mb is fine for WinXP but 1gb makes it hum right along.\n\nHope this helps.\n\nJust a note, you cannot use DDR2.  It is not physically the same, the slots the memory installs in are different configurations.
448357
First, it's 128 MB memory, but 16 meg is being shared for video. \n\nUpgrades of your system memory depend exclusively on your motherboard, so check your board's owners guide or the board manufacturer's web site for the total amount you can upgrade to.
581526
go to http://www.sisoftware.co.uk/ for a excelent tool which will give you modules for every part of your p.c including motherboard,it also gives you your windows product key which is handy to know if you havent got one\n      this also gives info like max memory that can be fitted and graphic card info
396188
easy...\n\ngo to kingston.com and use their ram wizard...  No guess work.\n\nAnoosh's suggestion just uses the system info in the registry.  It can be inaccurate.
1113406
go to bios and check the memory (ram) and \n\nfloppy drive conection to you mother board...
667514
Article on how to install memory module\n\nhttp://www.pcmech.com/byopc/step/7/...
520485
Run the Crucial Memory Advisor - http://www.crucial.com/promo/index.asp?prog=desktop2
5436
I would recommend going to http://www.crucial.com/index.asp and using their memory finder if you ever have another question like this.  They also have an auto detect memory feature (see sources) if you don't know the model number or it's a custom built computer.  Once you know, then buy it cheaper somewhere else like newegg.  Give a man a fish and all that...
861465
go to http://www.crucial.com and  it will tell you the excat amount of memory your system uses and the type
462091
OOH, No stickers?!!?  There I dunno how you will.  Best way is to ask a computer dealer to try the RAM for you and give you the specs.\n\nOr better, try it at a friend's who's willing to help u out.
941251
http://computer.howstuffworks.com/question175.htm\nhttp://computer.howstuffworks.com/ram.htm
1024571
It works.  How do I know?  I run this setup in my system.\n\nMemory modules typically have no problems running at a slower rate.  The only issue maybe be that SPD (Serial Presence Detect) or the configuration that the RAM has stored internally may need to be overriden in BIOS.  If your motherboard is set to use SPD setting, it may try to run the RAM at PC3200 if your motherboard supports it.\n\nI manually set the setting on my computer to run it at PC2700 in BIOS and it was good to go. \n\nSide note: I could have ran it as PC3200 but I wanted my computer to run SYNCHRONOUSLY (i.e. FSB and Memory Clock running at the same rate.) instead of running the FSB at 333 and Memory at 400.
628387
if the laptop was "off the shelf" (dell, ibm, compaq, hp, etc) you can use a wizard like the one at crucial.com to find out what your PC's memory type and maximum is. they have nearly all makes & models online, you just drill down thru a series of menus to find your particular one.\n\nif the laptop was custom-built you'll have to find out the manufacturer & model number of your board and do a little research, likely at the manufacturer's website.