You didn't give enough info to know if you can upgrade your memory or not. If you know your computer/motherboard model number then a 1 minute or less Google search should give you the answer anyway.
My system configuration is follows,
Gateway E series
Windows XP Professional; 2.4GHz Intel P4; 2GB DDR SDRAM 266MHz; integrated Intel 845G/GL 64MB (shared memory); Seagate 500GB hard drive, Samsung DVD r/w