If you use a network card, and its connected reliably all the time, you could see how long your connection has been active... Network Connections > Double click your NIC Entry..
For fun, my PII 400, with 256megs RAM has been running for 104 days now, with daily use, such as webdesign (photoshop, dreamweaver mx), gaming (half-life tfc, rtcw, simcity 4), and webserving (5 active websites, apache, php, perl, and mysql).. All powered by XP
