this is solved..

i had a file giving "access is denied" or in use by another process
errors when I tried to delete it. I did CTRL+ALT+DELETE and end tasked
explorer and tried to delete from command prompt (like eldergeek
suggests). but no luck.. I coudln't copy from command line either. I
was considering safe mode but I have never had to, it shouldn't be
necessary. I checked with sysinternals process explorer, "find..find
handle" c:\blah , and up pops the file within c:\blah apparently
used by "explorer.exe". Strange, since I end tasked it.

After quitting my remote desktop session, I came to a blank screen
*problem solved* !!
it is if explorer.exe had been closed on the client machine - (the one
i'm sitting on is the client, connecting to the server). And that was
indeed te case.
in remote desktop, CTRL+ALT+DELETE had opened up task manager on the
client machine, I should've seen from the bottom taskbar, it switches
to the client machine too. And msttsc.exe was listed in that box too -
which i hadn't noticed, but that indicates it was the client. So I
had closed eplorer.exe on that.

To do CTRL+ALT+DELETE on the machine you are logged into - as google
told me - it's CTRL+ALT+END