I've been using Windows 7 x64 for about 5-6 months on this system with no problems logging in to my account. I absolutely know with 100% certainty what my account password is, and how to type it. My password is a certain word, all lowercase. It was definitely originally set with CAPS LOCK off, and I almost never have CAPS LOCK enabled. No one but me has access to this PC.
While browsing the web tonight, I started to get some odd mouse and/or keyboard behavior. My mouse scroll wheel stopped working, and when I moved the mouse around it would select text even when I wasn't holding a button down. Also, clicking on apps in the taskbar was doing odd things like opening new windows instead of just switching to the active application. Since I could tell something was acting flaky, I tried a system reboot.
Only to find that Windows 7 was telling me my account password was invalid. I verified that CAPS LOCK was NOT on. But I could still not log in with my password. I tried another reboot with the same result. After many failed attempts, I was able to log in, but only after settting CAPS LOCK to ON. Even though my password was orignally set with 100% certainty and confidence as all lower case, with CAPS LOCK OFF. I have never used CAPS LOCK ON to log in to this account.
How would Windows switch my password to be in all caps, readable only with CAPS LOCK on? This makes no sense. Keyboard functions normally in apps like notepad, this forum, etc. It's a generic USB keyboard. No malware or viruses came up on a scan.
Thanks for any input.