Hi everyone, I have 4 gigs of ram, and my computer properties are only telling me 3.25. I decided to investigate further. I reseated all my ram, then checked the BIOS. It was reading 4 gigs! So then I went back to windows XP, and still 3.25 gigs! Any thoughts?
Windows XP does not recognize more than 3.25 gigs of RAM.
This is because XP is a 32bit operating system, so the maximum theoretical amount of recognized RAM is 2^32= 4GB. Subtract some overhead (someone else here is sure to be able to explain what that overhead is exactly) and you're at 3.25GB.
If you want to make use of all your available RAM, or install more, then you will need to use a 64bit OS.
You really should use the Search function but I will answer your Question as best I can. 32 BIT operation systems like XP and even Vista 32 only report 3.xx GB of RAM. The amount past 3 GB is different and depends on the MB manufacturer. This is due to the BIOS and what it reserves. Most PC's show between 3.25 and 3.5 GB when 4GB or more are installed. I will say that my Vista 32 Business install saw 3.5GB (out of 4 GB) but I now see 4GB after I installed Vista SP1.