When my laptop hard disk suddenly became too full to carry out Windows updates, I remembered reading the following on the VFR forums:
I deleted them all and all was good, my laptop was able to complete updatesThe problem is when you download Garmin map updates they go into a temporary folder, BUT after the update is complete these huge files are not deleted. Using the method below I recovered over 60GB of disc space!
1. Press the Windows key + "R" to open the "Run" command.
2. Type in %programdata%\garmin\coreservice\downloads\map and then press "Enter".
(Or you can use file explorer to go to C:\programdata\garmin\coreservice\downloads\map.)
3. Here it will list all the maps (in folders) it still has stored in temporary memory. Just have a look at the size! Right-click on a map folder you want deleted.
4. Select "Delete".
5. When prompted, confirm you want to delete the folder.
Now, the map should be in your recycle bin. If you empty it, you will gain space back on your hard drive.