DIAGRAM FOR A LABELLED 512MB RAM

If you added another 512Mb RAM to increase the RAM to 1Gb then the new 512Mb memory stick could be incompatible with the original 512Mb or it could be faulty.
Use RAM that is same make and speed as the original RAM.
Remove both RAM and just insert the new 512Mb into your laptop and see if the laptop boots up, if not then the RAM could be faulty.

Maybe you are referring to the video card? Or even RAM? If it is RAM you should definitely be using the 512MB (4 X 512) by this time. It is an older board, an ASUS (USA) no longer has a detailed specs webpage for this model. Make sure to check your manual.

Found this one:
http://reviews.cnet.com/motherboards/asus-p4s533-x-motherboard/4507-3049_7-30641017.html

If you are referring to computer RAM always put the largest ram module closest the CPU central processing unit

try to keep the same brand and type of ram the same ie: ddr ddr3.......
you will be able to read the ram type on the ram already inside

make sure you secure the ram modules by pressing the levers down firmly at both ends of of there sockets

make sure your computer is turned of before you attempt this
be sure to wear an earth strap before touching anything inside your computer
the ram modules sockets are located near your cpu

If you're not sure if a module is right for your system, use the Crucial Memory Advisor tool for a list of guaranteed compatible modules.

hope this helps you

Just had same problem. Found a solution:
I have an old HP Compaq dc5000MT. It has 4 RAM slots
Here's what DIDN'T work:
1gb + 1gb + 512mb + 512mb
1gb + 512mb + 512mb + 1gb
512mb + 1gb + 1gb + 512mb
Here's what DID work:
1gb + 512mb + 1gb + 512mb
I'm sure that:
512mb + 1gb + 512mb + 1gb would probably work as well.
From my guess they're are 2 "channels" (slots 1&2 are channel 1, slots 3&4 are channel 2) and you have to keep the amount of RAM balanced on both slots and in the same order.
Another thing to note with the old XP OS. IT ONLY WORKS WITH 3GB or RAM. MAX. So 1 + 1 + 1 + 1 (4gb) WILL NOT WORK... PERIOD for XP. Vista, 7, 8 etc. allows you to use a ton more ram + readyboost. They need all the help they can get though since they are major resource hogs.

i guess u have 2 different RAM cards in the RAM slots....
the main issue is both dont work together...the primary reason is compatibility....or one of the RAM cards have worn out...
u must use exactly similar kind of RAMs in both slots....
i suggest u use one 512 MB if your motherboard supports....
RAM technology has advanced so mush that you wont get RAMs for old PCs (motherboards)....so u decide...
pls revert back...and kindly leave a feedback and rating for this solution...it will help me move to Guru" here from Expert at Fixya....
regards...

Cant find your motherboard on the support page, is the memory your trying to install the same speed?

Maybe u can change ur ram or u can reinstall your system its better to install windows 7 64 Bit
Thanks

I assume the laptop had originally 256Mb RAM and you put 512Mb RAM in a the spare memory slot and you expected to see 768Mb of memory, is this correct? Try removing the 256Mb memory module and insert the 512Mb memory module and see if the laptop boots up with 512Mb of RAM. If it doesn't boot up then the RAM is either incompatible or faulty. Try using RAM modules from the same manufacturer.

firstly you need to make sure *********** board has a PCIe slot or a AGP... this is where your ATI HD3650 will go...see the graphic 512mb has nothing to with your main system RAM which is also 512mb.. so they wont be any problems as such and both will work together without any problems... but i suggest you to add another 512mb to your system RAM.. the difference between DDR and DDR2 is that... DDR2 is a bit newer and is faster in terms of memory read/write/access... do let me know if u have any futher problems....

The RAM speed of the new chips is too fast. You need the slower either 266mhz or 333mhz RAM speed to make your system stable again. Hope this helps.