"Hard error"? + unable to access F-fox...

Mornin', Folks...
How weird. Last night I got an error window from my computer (not from a website/pop-up) saying "Hard error". I think it might've even said "Network Hard Error". I'd close it out and it kept popping back up. I ended up shutting down.

This morning it was still there when I tried to get on line. It took several reboots, allowing the PC to clean up files, etc. Unfortunately when I try to open FireFox I get a message "firefox is already running. You need to close out firefox to open another window." But, there is no FF running that I can see. I've restarted several time. Finally got online thru IE and that, too, took two tries, still getting the Hard Error message and a freeze up one time.

I have a DSL modem (semi-highspeed). I have no idea what the hard error could refer to. Any idea? And why would I get a message FF is running when I have no windows open in it? I've opened Task Manager and there was nothing listed there. Now that I'm online via IE I checked Task Manager again and it shows the 3 windows I have open in IE but nothing shows in FF.

I reset the computer twice; one time it completely froze so I turned it off from the on/off button, couldn't go thru Start/shutdown series.

I can access my Gmail account thru IE but for some reason can't open my Hotmail account, probably due to running IE6 and not a newer version. Unfortunately Win2k won't support the newer versions. Bad news, eh?

Any idea what could cause this inability to open FF? What is Hard error?
Thanks
Shoe