hello prodikal..my servers seems working fine now. but then i'll try to answer your questions for info.
about a year before i got here, they have a mail server (set up on the same box i mentioned, and still using that as a server right now, but without the mail server solely for web) and is reported from the provider of the DSL that the server was being zombied. we tried formatting that with a new OS (XP) as a server still. days ago, i've noticed some folders on my webserver's document root. and is nothing to do with our website. good thing they didn't touch anything with our website and deface it. "they" we're only there to make use of my server and use it as a link to their files and causing my box to move slow (46 files of 40MB each). they've put up some sort of a DVD ripped files. and later found out that they reside in a french country.

i've used the tools u all AO's suggested and i hope my box work fine. thanks a lot for the help.