1. What operating system are you running?
2. Are you up to date with your Windows Updates, if you are running Windows?
3. What security software have you had enabled on your T61, and if you are running Vista, are you logged in with Administrator privileges, or as a normal user? Did you run any new, torrented software recently?
As you noted, if you have only moderately affirmative responses to the above questions, you could easily have a serious malware problem, and you should follow procedures at forums like aumha.net or dslreports.com to see whether you can eliminate that as a probable cause.
On the other hand, I know exactly the symptoms you are describing from personal experience. It happened to my T61p about me three weeks ago. I could click, but the HDD would not even flinch. In my case, the irony is, if it was malware, it could easily have come from a troubleshooting ISO that someone with good intentions pointed me toward on a torrent (to run a totally unrelated hardware performance test). I found no signs of any malware; it still could have been a virus on the master boot record (MBR).
Out of curiosity -- see if you can open a program this way: Open Task Manager (by pressing CTRL+ALT+DEL), and then click on the Performance Tab, and then on Resource Monitor. When RM opens, click on "Resource View Help." You'll see a help entry open up that has an internet link. If you click on that link, does Internet Explorer launch? It did for me. And I found that from within Internet Explorer, I could click on the Help icon (top right), and from there, search for any help-related term that might pull up a guide that had a link in it that would open up a program. For instance, you might find entries in help that say, "Click here to launch such-and-such a program." It's pathetic sounding, but that might give you a little more breathing room, if you need it.
Two other questions, though, that might be signs of something else:
4. Did you get any signs of trouble before this? Like lock-ups / freezes / blue error screens?
5. Did Windows just finish running an intensive Checkdisk (chkdsk) scan of your hard drives?
Prior to that meltdown on my Vista installation, there had been some instability. I'd gotten a bunch of hard drive lock-ups -- totally out of the blue, and seemingly unassociated with Active System Protection / Matrix Storage Manager bugs. I was even plugged in. I just had to do a hard power off each time. Then I ran chkdsk to look for hard drive trouble, and it was curtains for the OS.
It would be really useful to hear what condition your laptop was in on these specific fronts when you got this problem. But in the end, I just had to reinstall the OS. Short of that, you could insert your original Windows DVD, and run some repair diagnostics. There's a slim chance it could restore some functionality.
Also, did you try logging in under a different user account (or creating one and logging in through the new one)?
GOOD LUCK!
