Unclickable icons, unresponsive start menu, unresponsive start button, taksbar icons unresponsive or missing/invisible, system tray doesn't come up...you name it=corrupt OS, provided malware hasn't come onboard.
I tend to disconnect from the www before the OS install, once in OS GUI, I pop out a pen drive that houses all necessary drivers for my platform and install them manually in an elevated command, i.e, Right click installer>Run as Administrator. Once all drivers are installed, I connect to the www then run OS update.