There are two explanations. Uninstalling in reverse order will find one explanation but is a little harder to do than a better way. So some background first.
Hotkeys are also known as accelerators or shortcut keys. There are two general types of hotkeys. Application hotkeys and global hotkeys.
Application hotkeys are application specific and can't be changed (at least not easily). If you must change it then get a program like Resource Hacker and edit the hotkey table in the application. Not all hotkeys are set in this table, some are set by code and you can't change these.
There are two types of global hotkeys. Application registered and window (as in what you see on the monitor) registered. When a hotkey is pressed the application that registered it is activated and sent a message that a key has been pressed. Windows when they are created can also have a hotkey assigned.
When a user sets a hotkey they are telling Explorer (the program that does the desktop, start menu, and taskbar) to register the hotkey to explorer, and explorer starts the program, and then assigns the hotkey to the window that is created.
Explorer looks in only 4 places for user defined hotkeys. The per user and all user's start menu and desktop (and subfolders). However if it starts a program that has a hotkey assigned it will register that hotkey to the window.
E.G. If there is a shortcut on the start menu to notepad that has a hotkey assigned, pressing that hotkey starts the program. Pressing it later while the program is still running will switch to that program (as explorer then registered that key to the window). If the shortcut is somewhere that explorer does not look (like the Quick Launch bar) the hotkey does not get registered. However if you start the program from this shortcut its hotkey is registered to the window.
Below is a list of hotkeys that can start programs. If you need to list all user hotkeys see the Diagnostics section as it will be slow as all files need to be examined. Also Internet Shortcuts aren't included due to speed reasons. The Diagnostics section does list these as well. [ps you need to use the hta to run any programs embedded in this document - it is attached - see hotkeys and diagnostic sections - Diagnostic's diagnostic can take a half hour to run while the program appears crashed, Hotkeys's diagnostic takes about a minute (hence the reason for two diags - a quick one of most likely areas and a slow one of everywhere).]
If it is not explorer then it is another program. Easier than uninstalling is "clean boot troubleshooting" (type in help while online) - as a program must run to take global hotkeys you only need to stop it running rather than uninstall.
They can be other obscure causes (keyboard drivers/enhancements or language issues) and also application specific causes. Many keyboards come with F keys disabled by default these days and one has to press a FLock key to enable.
