as long as that you feel that your computer is good..you can keep it..and if you feel you need to upgrade your computer, just upgrade it.
i have Core2duo 2.66 Intel 2GB ram 256 VGA card 17" LCD TFT and with Super box and its only 6 Months Old and working great
My PC is almost a year old. Intel Core 2 Duo E6600 @ 2.4ghz 2GB RAM 2x300gb HDD RAID 1 I'd like to upgrade to a quad core Q6600 one day, swap out the motherboard, install a 64-bit OS, and upgrade the RAM to 4GB until I have to upgrade to 8GB and so on..
To be honest I had a computer from 97 up until november of last year, it was still running Windows 95. I couldn't even use the latest IE or Firefox or Opera on it. After it crashed from a keyboard malfunction I got a new computer. Its a Dual Core 2.1 GHZ with 4mb of L2 Cach and 2 gb of ram on Windows XP (Didn't want vista).