i have a folder called .WDtemp that has over 200GB of data on my C drive> Can I delete it.
Look at this prior topic/discussion, .WDtemp File .
You can also do a search about WDtemp by using the search icon at the top of this page.
Yes , you can delete it , it’s a known bug in WDSynch which doesn’t clean up after itself , I personally would stop using WDSynch until it’s fixed and use something like freefilesynch on a timed backup schedule (hourly perhaps).
It has way more options and is a lot less problematic.