Here’s how you verify windows xp system uptime i.e how do you know that how long is your system is running when you have done last boot. Here is the trick you can work in your XP machine:
Click Start | Run and type cmd to open a command prompt. At the prompt, type systeminfo
Scroll down the list of information to the line that says System Up Time.
This will tell you in days, hours, minutes and seconds how long the system has been up.
Note that this command only works in XP Professional, not in XP Home or any of other Windows Operating system to show system uptime. You can, however, type net statistics workstation at the prompt in Home. The first line will tell you the day and time that the system came online.