Windows XP does not recognize memory upgrade

[SocialAbility]

I had upgraded my system memory to 4GB from 2GB. I just added one more stick of 2GB RAM. But due to some issue the ram remains undected. In BIOS I can see 4GB RAM, but in Windows it just 2GB. This is very annoying. I contacted the seller who told me that it is a working hardware and there is no issue in it. So the problem lies in my system. Anyone knows why this happen. How to make XP to use both ram sticks.

[Borgnine]

That is a common issue with XP. XP is not capable of using more than 3GB of ram. It is the OS limit and you cannot do anything in that. You can try to upgrade your bios or simply add some Windows tweaks, but the do not help much. What is your motherboard model. If you are having any manual of that hardware in that you can find the ram specification. On that basis compare the new ram. If it does not match then that can also cause the missing problem.

[Gregoryl]

The problem lies with 32bit architecture. There is nothing you can do. You can find ample of information on that web that shows why this limit appears. There is a complicated technical term described on this but somehow it is easy to understand. In short it is a hardware limit. You can keep that 2GB ram for future usage.