Since I last posted I have not had a problem again 
I would suggest everyone keeps a backup copy of the C:\Users\<USER>\AppData\Local\TileDataLayer\Database folder so they can restore it if required, which will also preserve any customisations to the start menu.
And having an extra admin user always ready for use when required!
I have done exactly as ScotJ1 has detailed, however I restored the folder on one occasion with windows shut down by mounting pvm file on the mac using ( open with > parallels mounter app ). so I could recover the database folder from a previous snapshot. This helps if windows is locking the files.
From memory!
1. Shut down windows
2. Create a new linked clone from a working snapshot
3. Open this new pvm with parallels mounter and copy the user data folder to another safe place.
4. Open normal windows 10 pvm with parallels mounter and replace retrieved database folder.
5. Un-mount the as you wound and other disc.
6. Start repaired windows 10
7. Delete linked clone.
I would suggest everyone keeps a backup copy of the C:\Users\<USER>\AppData\Local\TileDataLayer\Database folder so they can restore it if required, which will also preserve any customisations to the start menu.
And having an extra admin user always ready for use when required!
I have done exactly as ScotJ1 has detailed, however I restored the folder on one occasion with windows shut down by mounting pvm file on the mac using ( open with > parallels mounter app ). so I could recover the database folder from a previous snapshot. This helps if windows is locking the files.
From memory!
1. Shut down windows
2. Create a new linked clone from a working snapshot
3. Open this new pvm with parallels mounter and copy the user data folder to another safe place.
4. Open normal windows 10 pvm with parallels mounter and replace retrieved database folder.
5. Un-mount the as you wound and other disc.
6. Start repaired windows 10
7. Delete linked clone.