Security-Compromised NT System [what can they see?]

From: SN (
Date: 02/20/02

From: (SN)
Date: 19 Feb 2002 21:36:45 -0800

Hey all you Windows/NT gurus out there. Can you shed some light on
this issue for me.

I work on a company provided Windows NT4.0 computer that I didn't
install the OS and the Administrator password [was] known by more than
one person, although the computer is primarily to be used by me only
as a development machine. It just so happens that I sometimes do
fairly personal thing on this computer, e.g. read my web based email,
etc. Since the computer is compromised. Can they also see what I am
reading in my emails? (assuming these people don't have access to the
company routers/firewalls which would have been easy to see all the
webpage that I watched). They only have access to my computer, and I
assume they have planted Trojan horses and stuffs.

Am I safe to secure my files using PGP conventional encryption, ie. no
keys lying around anywhere on the computer. However when I encrypt
the important files I have to type in the password using the keyboard.
 Can they install a program to watch what I typed when I keyed in my
password [passphrase] when I conventionally encrypt a sensitive file
using PGP??

How do I implement counter-measures, any softwares that will let me
know if my keypress are being logged? Unfortunately I am not allowed
to reinstall Windows NT on this system, I once brought in softwares to
reinstall but the enemy had the management ordered me to stop. Until
I find a new job (I am working on this), I need some kind of
counter-measures. Any advice? THanks in advance.