This ONE is weird and I am not sure where to go next - long story short - Ex roomate that has 25 years+ programming, unemployed, bored, (criminal?) networked my laptop and desktop into his computers. I did not realize the scope of it for 6-7 months and starting looking into it when my laptop was running slow. I discovered that he had more admin/domain authority that I did. ASKED him to take me off network and he would not. Discovered hidden partitioned 4 GB area on both. Longer story short - I moved, reformatted laptop, NEW hard drive on other, windows XP prof.  Have had 5 "techs" to my house who say that they are securing my system. My roomate was also linked up to my desktop with router.  I then proceed to find ADDITIONAL passwords in my system - computer name changed, remote access turned on after I turn off - etc. I am running Norton and can see some stuff that bypasses Norton - backdoor g-1-1354, port 9000, remote services running that I as Admin cannot turn off, etc. This is where it gets weird. He locked me out of my Pronto remote control, locked me out of my cellphone (will change both asap) and had asked me for a bluetooth device for my phone that I ran over in my garage and was going to throw away. My last computer was also a new one - I found weird stuff in that one also - IS there any WAY for him to get in through neighbors unsecured wireless or through automating something in regards to remote controller? I have to stretch as this is frustrating - I have a business and have had no usuage for 6 weeks. Network security specialist?? If there is 1 minute unsecured when Norton is being updated or router is being set up can he get in? Please any info is welcome for this bizarre and frustrating situation.Oh dear!

Your easiest option is to completely frag the hard drive of any machine he has touched.  Also reset and reconfigure any router that he's had the use of.

On the hard drive front, reformatting is not enough.  You must delete the partitions (using FDISK, or XP's installation routine) and start again.

I don't know where in the world you're based, but your ex-room mate's activities would certainly be illegal in the UK.Before you start removing things, go talk to your police officers. This is very serious and you will probably need them as evidence. Personally, I'd advise against wireless in the future.This is easy.

Grab him by the throat and.... ummm, use your imagination 8-)

That may limit your legal options though.

Well actually I think Neil's suggestion is probably the best thing to do.