psinfo is another easy way to check the OS and SP level of a remote machine (assuming you are using Windows). You could also just connect via computer management but its a bit more of a hassle.
Code:
C:\>psinfo \\remote_host
PsInfo 1.34 - local and remote system information viewer
Copyright (C) 2001-2002 Mark Russinovich
Sysinternals - www.sysinternals.com
System information for \\remote_host:
Uptime: 1 day, 8 hours, 33 minutes, 19 seconds
Kernel version: Microsoft Windows XP, Uniprocessor Free
Product type: Professional
Product version: 5.1
Service pack: 1
Kernel build number: 2600
Registered organization:
Registered owner: IT-Support
Install date: 02/01/2003, 15:59:59
Activation status: Activated
IE version: 6.0000
System root: C:\WINNT
Processors: 1
Processor speed: 800 MHz
Processor type: AMD Duron
Physical memory: 256 MB
Regards
eddy