Windows 7 Taskbar icons not showing

You want to delete all of the iconcache*.db files in the explorer directory. Reboot and they should auto rebuild.

Thanks, Kemical and Neemobeer. Neemobeer - I rebuilt the db files properly, making sure explorer.exe was not running.
Kemical - I've had trouble with built-in windows utilities in the past (they often end up changing my settings) and think the simplest thing to do is overwrite the messed up files with a recent backup made before this problem started. Can I just replace the c:/windows folder? I'm guessing all files and registry settings affecting the taskbar are in in that folder but want to check.

Just to verify, do the shortcuts work and the icons are just missing or are the shortcuts broken as well?

If you add a new pinned icon does it work?


Additional Info about the taskbar.
Icons cached
C:\Users\<username>\AppData\Local\Microsoft\Windows\Explorer

Pinned shortcut LNK files
C:\Users\<username>\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch
C:\Users\<username>\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch\User Pinned

Pinned Shortcut Mapping
Registry
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Taskband
Value Name: Favorites
Value Type REG_BINATY

If the mappings are screwed up you may not see icons

Thanks so much for your help. Here's the information you asked for.

The shortcuts work but the icons on the taskbar to the left of the notification area are missing. I can pin a shortcut to the taskbar and it works immediately but doesn't remain on a reboot (though the shortcut still works on my start menu, with the keyboard shortcut I assigned to it and a desktop icon). The shortcuts are also in this folder. The ones I pinned after the problem started are in there too with the number 2 in parentheses after their names.
C:\Users\(user-name)\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch\User Pinned\TaskBar

A few others are in: C:\Users\(user-name)\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch\

(Some are in bothy ...\taskbar and ....\quick launch)

C:\Users\<username>\AppData\Local\Microsoft\Windows\Explorer contains:
ExplorerStartupLog_RunOnce.etl, thumbcache_96.db, thumbcache_256.db, thumbcache_1024.db,
thumbcache_32.db, thumbcache_idx.db, thumbcache_sr.db, ExplorerStartupLog.etl
The most recent of the thumbcache files, thumbcache_32.db, is from April 2017.

The taskband registry key contains: Favorites (reg_binary), FavoritesChanges (reg_dword), FavoritesRemovedChanges (reg_dword), FavoritiesVersion (reg_dword).

Can I do anything with any of this stuff or go with a restore of the windows folder?

Update: I ran sfc /verifyonly and it found no problems so I tried a system restore. Running it from windows, it reported to could not complete. I ran it in safe mode and it reported that it could not complete, but whatever it was able to do it brought the icons back. It also took away my administrative privileges. At this point I'm going to restore my c: drive from an image, which I hope will fix everything. Thanks for all help.