1.5 Gb Ram Limitation - Win XP

I’m running Cubase 5.5.2 in win Xp 32 bit and my system has 4 Gb of ram. Cubase crashes every time it uses more than 1.3Gb of ram. (According to Windows Task Manager). does anybody with winxp 32 facing same problem? I’m assuming its a problem with Cubase and not with my system, because I can use up to 2GB of ram inside Fl studio.
Does Enabling 3GB switch fix the problem?
I really appreciate any helps or comments.

Get Jbridge. Then you can use all your ram as far as apps go. It will allot 2g per app until you reach your ram limit.
All of 15-20usd.

Download Jbridge and test all your plugins first, so you know they are compatible.