Google Login problem

First I should mention that I have a laptop with Windows 7 and a Mac. Today I tried to log in to my Google account on the Windows 7 laptop. Google did not accept my password. I checked my typing & all caps, it was fine, still no go after several attempts. I followed their help steps but Google didn't like my answers to security questions (I have no idea when I opened the account). I shut down the Windows 7 and went to the Mac and was able to log in there. Does this make any sense at all?
After doing that I was then able to log in on my Windows as well. To make this really simple for you I'll make my question multiple choice:
a) there is nothing wrong with your computer or Google account - it had to be an error on your part.
b) there may have been an issue but you've gotten past it and you're good to go.
c) although you're able to log in again, there might be a malware issue.
Thanks,
Plite

p.s. two probably unrelated things: I mistakenly clicked on an AVG toolbar downloader yesterday which replaced my Firefox until I uninstalled it; I noticed that my Google home page was the non-secure one (http://www.google.com/webhp?nord=1). It was https before this.

 

:-oI think you're right about this being a PEBKAC problem.
Thanks!
Plite