Many system administrators have had this problem. Your server was preconfigured with only 10GB for the primary parition where Windows is installed. Meanwhile the secondary partition has 36 Terabytes of free space. WTF? Yeah it sucks and of course the admin before you installed Backup exec and virus protection to c:\program files - nice. Anyway I've been there and the answer is to move important programs off asap. Fortunately for my experiences I never had to take it to the next level.
Tonight I had an issue where the C: drive was almost full and there really wasn't much else I could remove. I was thinking of using Partition Magic or some other 3rd party software. First of all let me say 'Why does Windows not have this support just built in?' It would be so great to have Windows allow me to only the fly adjust and resize partitions. Next version of Windows server... PUT THAT IN!!
Anyway I should also mention that on this server we use Symantec Endpoint protection. So I do my search for any files over 10MB and I find a huge problem - Symantec was flooding my hard drive with log files. If you use Symantec Endpoint protection this is a major tip for you or if you run IIS on a server. Make sure for the love of god you mind your IIS logs. When I looked in C:\WINDOWS\system32\LogFiles\W3SVC2 I found literally 3GB of logs. Delete them! Then go into IIS and turn off logging (unless you need it). If you run a web server and actually host a web site (install of just use it for Symantec Endpoint protection) you may want your log files, thats fine - but move them off the C drive.
So that's my tip : If you are running out of hard drive space and use IIS please check your logs, if you don't need them - delete them. Good night.
