Quick Access folders missing

Hi, have you tried pinning any new folders to Quick Access? They are just a convenience- losing them is not earth-shatteringly vital, so you choose what you want there.
https://support.microsoft.com/en-us/...n-quick-access

You could try
http://www.thewindowsclub.com/quick-...is-not-working

Found by searching for
repair quick access

Somehow thought it wouldn't, but start with the smaller steps and go on.

Since we don't know what else you have tweaked that might be a problem, and you don't have a registry backup, system restore points, and presumably don't yet have system or disk images (very very strongly recommended by all here) I would suggest an in-place upgrade repair install, unless you can search for and find an appropriate specific repair.

Precede it with this in case sthg has happened to your file system:

From an admin command prompt
[Windows key + X, click command prompt (admin)]
chkdsk C: /F
Your PC will need to restart.
Make sure the result is clear or fixed.
Post back the result, which will be on the screen briefly.
Otherwise you can get the result as follows:
How do I see the results of a CHKDSK that ran on boot? - Ask Leo!

An In-place upgrade repair install will fix many things, but not those where the settings are not changed by the procedure.

For this you need an installation medium with the same base build as you have installed.

Repair Install Windows 10 with an In-place Upgrade - Windows 10 Forums

This will refresh Windows, after the manner of a Windows installation.
- all/most associations will be unchanged
- all your programs will be left installed
- you will lose any custom fonts
- you will lose any customised system icons
- you may need to re-establish your Wi-Fi connection
- you will need to redo Windows updates subsequent to the build you have used for the repair install
- Windows.old will be created
- system restore will be turned off- you should turn it on again and I recommend you manually schedule a daily restore point.
- you will need to redo any language downloads including the display language if you changed that)
- inactive title bar colouring (if used) will be reset to default
- if Qttabbar is installed, you need to re-enable it in explorer (Options, check Qttabbar)
This is one of the better features of Win10: as each major build comes out, that's your updated reference build, and as updates are mostly cumulative, there will be few to do.

Recommendation:
Before you perform this major repair procedure, do create a disk image.

Please consider using disk imaging regularly. It's a brilliant way to
- preserve your system (and your sanity)
- back up your data
- restore your system to a previously working state in a relatively short time

Recommended: Macrium Reflect (free/commercial) + boot disk/device + large enough external storage medium.

Good.. it's often less painful and quicker restoring some kind of backup than finding a specific fix, which may or may not exist.