We have a SBS 2008 server that is being used as second server. Mainly just a file share and a webserver for a LOB app we use. The server is hanging with 99% memory usage and becoming unresponsive. Task manager and Resource manager don't show any programs using that much memory. The system has 32GB. I've ran RAMMAP and the File Summary, the top file, using nearly 28GB of RAM is the Shadowprotect backup file on an external hard drive. This problem only seems to happen when a USB drive is plugged in. If I unplug the USB drive and run backups to a file share on another server, there's no issue.
For reference, Exchange is not running and has been removed from this server. It's not a domain controller.