IIS could not add data to the log files in \%windir%\system32\logfile as the disk was full.
To increase the amount of available disk space, do one or more of the following:
Run Disk Cleanup to gain more free space on the disk.
Back up and remove files, or delete unnecessary files from the disk.
Move files to another disk or to offline storage.
Purchase additional storage or switch to a larger disk.
To view recent disk space history you can use the following view:
Start Disk Capacity View