Update: Well, after rebooting 5xs, unplugging my passport drive, replugging mouse/keyboard into different USB ports, all is well.
epilogue: What may be of interest to those similarly affected, was that once I'd gone safemode and rebooted normally, at the login display, where icons for accounts exist, my mouse moved, but couldn't actuate any profile icon (ie, none could be selected and open the password field). The keyboard didn't work at all (ie, ctl+alt+del wasn't an option). Only after physically turning PC off, followed by the actions described above, was I able to have both mouse & keyboard function . . but, now problem's solved.
I'm having a similar problem. I just rebooted my win 7 pc, and the mouse only works in safe mode. Prior to reboot, no s/w had been installed.
In safe mode, the driver for my HID-compliant mouse is "working properly" (location is USB Input Device).
Any suggestions? Thanks in advance!
ps, this happend last week on my laptop, which I resolved by holding down the WinKey+Fx (one of the F keys, I think it was 4 or 5).