With 4 GB of system RAM currently going for about $50, go to 4 if your motherboard will handle it.  XP is limited to using a bit over 3 GB, but some system overhead will load first.  32 bit XP cannot address space above 4 GB, so that's the real barrier.  You may not be able to use all 4 GB, but you will give your system as much as it can use.

Klebnor

Lotus 123 ~ S-Render ~ OS/2 WARP ~ IBM 8088 / 4.77 Mhz ~ Hercules Ultima graphics, Hitachi 10 MB HDD, 64K RAM, 12 in diagonal CRT Monitor (16 colors / 60 Hz refresh rate), 240 Watt PS, Dual 1.44 MB Floppies, 2 button mouse input device.  Beige horizontal case.  I don't display my unit.