Windows 8.1 on an HP desktop with Stopzilla security. Portable disk is Seagate Go-flex which suddenly converted to RAW.
Hi mgillman, and welcome to the forum.
If your drive comes up as RAW, then it means it's viewed by Windows as "Unallocated Space". Which means you have the option to attempt a restore of the partition on that drive using partitioning software.
If the software does find unallocated space then it will search that space for traces of the partition which has been lost. If that's successful, it will rewrite the MBR of the drive to restore that partition.
One or two "ifs" here, but I can assure you that I've restored lost partitions on my own drives over the years, and is something I would always try before going down the road of "Quick Formatting" the drive.
That's the last option, but could also work as neither "Quick Formatting" nor the above mentioned rewriting of the MBR would touch the file data contents on the drive.
A quick format would reinitialize the file system, give the drive a letter, thus enabling Recuva to scan it.
Have a look here for a number of free, reputable partition recovery programs.
https://forum.piriform.com/index.php?showtopic=47540&do=findComment&comment=279187
All these programs have detailed guides but if you get stuck I may be able to offer some assistance.
Hope that helps.