Uptime of a Windows machine

If just you want to know the time passed since the last boot, execute the bult-in command

 systeminfo

in a command line. Search for the "uptime" line.

EDIT: i just noticed your "after hybernation" requirement - sorry, I don't think this will take that into account. You'll need to work this out from reading the event log. Uptime is time since last reboot. A hibernation is not a reboot. If "uptime" could be defined to take hibernation into account, I would expect it to mean all time spent awake since the last reboot (meaning minus all hibernation time), not just the time since last hibernation.

I use the free psinfo tool from sysinternals (now owned by microsoft, and still free)

C:\>psinfo

PsInfo v1.75 - Local and remote system information viewer
Copyright (C) 2001-2007 Mark Russinovich
Sysinternals - www.sysinternals.com

System information for \\LAPTOP:
Uptime:                    0 days 11 hours 28 minutes 27 seconds
Kernel version:            Windows 7 Ultimate, Multiprocessor Free
Product type:              Professional
Product version:           6.1
Service pack:              0
Kernel build number:       7100
...

Grab it from \live.sysinternals.com\tools\psinfo.exe (you can even run it directly from that unc link).

1. Windows Uptime (free from MS) might help you with that, but I'm not sure if it will give you info about 'after' hybernation: http://support.microsoft.com/kb/232243

2. I wonder if the default tools might help you (from cmd):

   net statistics server or net statistics workstation