Problem

IIS logging is enabled by default. If the log files are not periodically deleted, then eventually, they will fill up the IIS drive.

Solution

To free up drive space, delete the logs at the following location:

C:\inetpub\logs\LogFiles\W3SVC1

Note, replace C: with the correct drive letter if IIS was not installed on the C drive

Optionally, disable IIS logging to prevent this in the future.

Steps for IIS 7:

Open IIS Manager
Select Default Web Site
Double click on IIS > Logging
Select Disable in the Actions pane (on the right)
Select the server name in the connections pane (on the left)
Select Restart in the Actions pane (note, this will end the web sessions for anyone connected to this server so only do this when everyone is okay with the disruption)