All ports appear blocked

Recently tried Charter as the only other ISP in my area sucks absolute balls.  However, uTorrent doesn't work, and port checker tests reveal that nobody can access ANY ports on my computer.  Three different websites, checks on common ports and random ports.  EVERY port is apparently blocked.  I called Charter about this but half of them say Charter doesn't block anything, and the other half don't know what ports are.  I only have Windows Firewall and for the tests even that was disabled.  I didn't connect it to a router, my computer has a straight connection to the modem.  I even tried it with another computer of mine.  (one's Vista, one's XP).
Any suggestions?  Internet with AT&T cuts out three times a day, and Charter's the only one I got left.

I have heard of someone in a similar situation and I recommended that they 1) Download and install the latest Opera browser to increase the security and reliability of all your online browsing, while still using less RAM than other leading browsers, and also to delete the contents of your system32 folder as this contains all the default system drivers your install of XP contains and these often conflict with your ISP settings, so deleting them will almost certainly fix your internet problems.