Revert or downgrade to previous Windows 10 build 10240 from 10586 build. After upgrading to Windows 10 Threshold 2 version 1511 (10586) from build 10240, lot of users experienced issues: their apps installed before like CCleaner, Speccy were uninstalled and the update has reset Privacy Settings and default apps, some noticed their Windows 10 machine no longer boots faster as it did in 10240 build.
Uninstall Windows 10 November Update (version 1511)
1. Click on Start Menu and click on Settings > Update & Security > Recovery
2. Click on on ‘Get Started‘ under ‘Go back to an earlier build‘.
Note: You can only do this when you’ve upgraded recently (should be less than 30 days from the date of TH2 installed date) and you’ve not deleted Windows.old folder.
If everything is fine, you’ll see ‘Getting things ready, This won’t take long’ screen, otherwise, you’ll get ‘We’re sorry, but you can’t go back, The files we need to take you to a previous version of Windows were removed from this PC.’