I really don't see what this has to do with
Windows XP
.......... it is about FORENSICS............. that's where an investigator is faced with a fait accompli not a choice. So, if Limewire or Bearshare is what youv'e got, that's what you run with.

As for Tor............. this is what they have to say about themselves:

There are three pieces of fine print you need to know about.

  1. Tor does not protect you if you do not use it correctly. Read our list of warnings and make sure to follow the instructions for your platform carefully.
  2. Even if you configure and use Tor correctly, there are still potential attacks that could compromise Tor's ability to protect you.
  3. No anonymity system is perfect these days, and Tor is no exception: you should not rely solely on the current Tor network if you really need strong anonymity.
Ipse Dixit?