Your machine probably ran Windows 98 as the hd size for this machine is approx 20gb. It's probably a pentium II maybe an early pIII. PII machines can even run Windows 7 if you're nuts enough to try it. Best upgrades are to ramp up the maximum memory and/or switch out the motherboard for one more recent vintage, given that a newer mobo will get you stuff like better USB and video its a good bet. Although Win98 will do networking, your best best with a wireless card is to have at least windows 2000 on it. 2k can handle hd up to the 137gb barrier. It is great game machine for those that wanna run older games that won't run on 2K or newer machines. You can stuff a whole lot of really cool games on it...such as Alpha Centauri, and others of those great Sid Meier games. You can do Office, and unless you are doing something memory intensive like chemistry or rocket trajectories it works great for just surfing the WEB or the occasional downloading you might do. PII machines generally can only handle about a quater gig of memory while a PIII can use a half gig...which is a factor if you open a lot of apps at once.