You're the very first one to report this problem and if Hotkeys is responsible for causing the trouble, I'm very sorry for that. I can't think of any reason why it should prevent Explorer from running.
There's an easy way to get rid of Hotkeys after installation. Simply delete the entire
"C:\Program Files\Hotkeys" folder from DOS. Something like DELTREE C:\PROGRA~1\HOTKEYS should do the trick.
Maybe Windows will complain on startup that it can't find the program Hotkeys.exe, but you can fix that by removing Hotkeys from the registry once Windows is started (remove the Hotkeys key in
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run).
If removing Hotkeys gets your system up and running again, I would appreciate it if you could send me details about your system (Windows version, computer type etc) so I can research why Hotkeys messed up your computer.