ok ihad a poblem last week took out my 256 and 128 and wanted to replace with 1.0gb . well didnt work each slot maxes out at 512,anyway iwant to take out the 1.0gb and send it back for 2 512s. but i am afraid. when i did this last week windows would not boot.i wonder if the hard drive did not reconize the new ram...i had to put in my old hard drive and copy it back to the new one..... windows that is. can anyone help me on this before i go thru all this again when changing ram......

Hi ozzymary, welcome to ItsAllPC

Provided you are using Windows 2000 or later, there should be no reason why you need to make any changes to your operating system when changing RAM. If you're using Windows 98 and earlier, more than 512MB of RAM doesn't really work anyway; even if it does detect it, it doesn't use it. If you are using Windows 2000 and later, a failure to boot into Windows with new memory usually points to a defective module. I feel like a broken MP3 saying this, but always always run a memory test (like Memtest86+) when installing new RAM. It’s totally not worth the trouble to find that its defective later on, and defective memory is ludicrously common.

Systems with a per-DIMM restriction of 512MB are quite old now; Pentium 3/Athlon days. With a system this old, it’s hard see the advantage of 1GB of RAM anyway.

iam using windows xp .so if i take out the 1.0gb and send it out to get 2 512 s it shouldnt hurt. i do have a anthalon 2400 2.0ghz.and when upgading from 128 to almost 750 a big differenceihave in my pc now a256 and a1.0gb(that will only read 512
the sytem isnt that old maybe 2years

You issue then is hard to understand.

There should be no problems changing RAM at all; if there is, you have a defective component or serious software issue somewhere. Furthermore, a system of only 2 years should support DIMM sizes of 1GB, unless there is a BIOS fault, which may have been fixed later.

What motherboard manufacturer model, or what chipset do you have?

here are my specs i have 2 slots each max out AT 512. CAN I FIX THIS SO IT WILL READ the entire 1.0gb thankx for your help
Product name s4020wm
U.S. Product number DK214A
Chassis (color) Mid-size tower- Pinehurst 2- Black/Gray
Color detail Black/Gray
Microprocessor Athlon XP 2400+ 2.0 GHz
Frontside Bus speed 266 MHz
Processor architecture Socket-A (PGA462)
Chipset KM266
Hard drive 40 GB
Drive RPM 5400 RPM
Memory 128 MB DDR SDRAM
Memory max 1 GB
Memory speed 2100 MB/Sec
Total DIMM sockets 2-184 pin
Available DIMM sockets 1-184 pin open
CD, DVD Rewritable drive CD-RW (32x/10x/40x)
Diskette drive 3.5 inches (1.44 MB)
Fax/Data modem Lucent V.92 56K modem
Network Realtek 8100L
Keyboard Compaq PS/2 Internet Keyboard
Mouse Internet Scroll Mouse – PS/2
Sound Realtek ALC201
Speakers N/A
Speaker form factor N/A
Total expansion slots Three PCI, AGP4x 1.5v
Available slots Two PCI, AGP4x 1.5v
Total drive bays Ext (two) 3.5 inches (two) 5.25 inches Int (one) 3.5 inches
Available drive bays 3.5 inches ext., 5.25 inches ext
Total external ports Serial, six USB 2.0, parallel, two PS/2
Available external ports Serial, six USB 2.0, parallel, IEEE 1394
Front mounted ports Two USB 2.0, IEEE 1394
Video graphics (AGP) VIA-S3
Graphics memory UMA 32 MB
Tower dimensions 16.55 x 6.88 x 14.5 inches (23.8 pounds)
Power supply 200 Watts


Software
Productivity and finance software
Microsoft Windows XP Home Edition
Microsoft Works 6.0
Microsoft Works 7.0
Microsoft Money 2002
Microsoft Encarta Encyclopedia Deluxe Online
Microsoft Encarta Encyclopedia 2003 Standard
Quicken New User Edition 2003
Adobe Acrobat Reader 5.0
Compaq Help and Support
PC-Doctor
Norton AntiVirus 2003
Detto Intellimover to migrate files from an old computer to your new Compaq Presario desktop PC easily (cable not included)
Music and multimedia software
MusicMatch Jukebox 7.1
Coloreal
RecordNow 4.5
Veritas DLA 3.6
Weatherbug
RealOne Player
Netscape 7.0
Yahoo Essentials
Preloaded ISP offerings
AOL 8.0 CD-ROM in the box
Haute Vitesse Internet (Broadband) Canada only
AOL (High Speed DSL and Satellite)
MSN
MS Internet Explorer Customization
Earthlink broadband
Aftermarket promos to include where there is room
Emusic icon w/URL
Compaq Offer Zone/Hot Deals
Disney desktop icon w/URL
Wild Tangent game channel

here is some more