Firefox is the only thing i tuned on my pc. And messed with some game settings, you know to make it quicker.
As for my pc:
Wind 98 second edition (all updates installed)
intel pentium 3 proccesor 800mhz
256mb ram
28.6 hd
nvidia riva tnt2 model 64 (64 mb i believe)
Is that enough or do you want more? I found this with dxdiag, form windows.