If the computer came with 1GB of ram it will likely need to be upgraded to play modern 3D games. But that era of computing can still enjoy a few rounds of UT2K3
We need to know the processor type and speed, motherboard chipset (if available), ram speed, and the current GPU (graphics card or integrated graphics) that you have.
If you do not know then go download PC Wizard by CPUID and it will have everything listed there.