Last night, I did a routine manual backup using Robocopy backing up and entire drive of a critical file server (windows 2008 r2) to a backup server on the same network. This morning (around an hour ago), I noticed the drive filled up on our backup server on our Zabbix monitoring system and Robocopy was showing a "not enough space on disk" error as expected. So I CTRL + C'd to cancel.
After I canceled, I noticed Zabbix told me that the critical file server was at 100% CPU usage! I checked Task Manager and noticed that explorer is giving a 58%-75% reading but not 100%. All other processes are at 0 or 1% not totaling 100%, but the total CPU usage is still at 100%.
I can't reboot the server unless I absolutely have to because hundreds of employees depend on this file server. I did some research and found that it may be due to a broken shortcut on the desktop, but I don't have any broken shortcuts.