Today's the day that taxes are due in the US -- somehow it seems [perversely?] fitting that parts of the country are experiencing an April snow storm.
Anyway... Wise Data Recovery Pro is a smallish app that comes in 32-bit & 64-bit versions, though the 64-bit one will still install in Program Files (x86), where 32-bit apps are supposed to go. A folder's added to Users\ [UserName]\ AppData\ Roaming\ that just stores a configuration file. Additions to the registry are a bit weird, adding what is a default major key, WOW6432Node, in unusual places -- added registry entries are also different between 32 & 64-bit versions. Running the app unregistered only adds a single registry key with a variable CLSID value, that may work to ID the device, while registering it adds the data in the normal places, so the weirdness is probably the result of preparing the GOTD version with registration data already filled in.
Installing the GOTD version of Wise Data Recovery Pro nonetheless only adds about 10 registry keys that each store minimal values or entries. The reason for slightly detailing the registry adds is in case it's useful to those wanting to run the software portably.
It's been a while, THANKFULLY, since I've needed a file recovery app because of a problem with a hard disk or other storage media. At that time I tried the various recovery apps I'd collected, mainly from GOTD, finding the results were very unpredictable -- they'd all tested fine, but those tests were all artificial, Not from file tables on the disk being damaged. The lessons learned were 1) it's a good thing I collected those apps, & 2) that's because there was no way to predict which one(s) would work best when I really needed to recover those lost files.