Password no longer recognized, sound gone, keyboard weirdness; Virus?

Since last night, my desktop Win 7 machine has lost sound -- strangely it first lost sound on my girlfriend's profile, then only later it went on my administrator's profile too. Now when I want to log in Windows won't recognize my password (interestingly, a little message comes up giving my reminder phrase for it, so there's no doubt about what the right password is or was). What happens too is that when I want to type in the password, the keystrokes multiply to infinity and fill the box with a single letter.
Have I got a Christmas present in the form of a virus or other infection ? I ran Spyhunter 5 and Microsoft Security Essentials when the troubles started with the loss of sound. Both of these are up to date. Spyhunter found one spyware cookie, MSE nothing at all.
I'm now writing this on my old laptop (also Win 7), though I can get into the problem desktop machine using my girlfriend's profile because, thankfully, that requires no password...


Grateful any helpful Yuletide suggestions.
Leachim

If it's filling the password box, as you said, then you wouldn't be able to provide your password correctly and boot in. Does that make sense?

It sounds like the type-ahead setting on your keyboard is screwed up. You might try disconnecting and reconnecting your keyboard in Safe Mode. Or you could try a system restore or last known good configuration.

Have you checked in Control Panel, Sound to make sure the correct device is configured and working properly?

Although it would often fill the password box, I was by typing carefully able to put the right password in.
I have now swapped that ancient keyboard for another less ancient, and although it no longer repeats letters so annoyingly, Windows still refuses to recognize my password. A message suggests I reinitialize the password using an USB drive, but that has to be configured specially. I will try to go down that road.
As regards the sound disappearance, I've checked all I can in control panel and the proprietary VIA sound system and also using DiagDx, and different speakers. Nothing.
My bro who was a computer pro says it sounds like a hardware/in-out system problem and suggested for starters to change the keyboard.
But what can be causing my password to no longer be recognized?
Does this proposed recourse for re-initializing the password work ? I'm hoping to be able create the right stuff on a USB stick from my Win 7 laptop...

Still can't get sound in the lady's profile on my desktop, whereas it works alright on my administrator's profile. I'm stuck.

When logged into her account, go to Control Panel, Sound. Select the sound device you're using and select Properties. Is the "use this device" enabled? If so, is the Speaker icon in the system tray? If so, click on it and select Mixer. Make sure that it's not muted and that sound lever is above zero for Windows sounds.

To clear the login password open Control Panel\All Control Panel Items\User Accounts select your account - change your password

Log in as your girlfriend
- Open device Control Panel\All Control Panel Items\Device Manager. Is there any yellow alerts?
- Control Panel\All Control Panel Items\Sound. Is the output mute?

Thanks too to Megahertz

leachim said:

I much appreciate your help and advice, Wither. I think I've done all you said and checked it all, and there's still no sound when I'm logged into her account. Sound's fine on my admin account, coming out of four speakers: two speakers in the screen for the rear left and right, and a couple of unpowered little ones left and right front. Sound is provided by a VIA onboard high definition chipset... but this looks like a software problem, right? A setting somewhere? I'm baffled.


Oh oh, feel a fool, just found a tiny mute button on Windows Media Player, clicked upon and lo, sound !


Hope 'tis a permanent fix. And at least I know the system better now.

Guess I told you to look to see if it's muted in the wrong place. I'm glad you found the solution.