A number of things here.
Firstly, posting into a thread that is now nearly a year old may not get you the help you need. Many members here just 'walk on by' when the see the date of the original post.
Secondly, since torrents and other P2P software are generally used to download copyrighted and pirated files and software, helping people who use torrents for such purposes contravenes Forum Policy. So unless you can convince members here that your downloaded files are genuinely free from copyright and are not pirated, and that you do not share files on your system that are similarly copyrighted or pirated, you may not get help for that reason.
Thirdly, I don't understand what a registry defrag has to do with internet connection speed. The registry in XP does not need constant defragmenting, and indeed, using registry optimisers can be dangerous. Deleting or amending the wrong key or value can leave your system unaccessible.
Finally, it is your internet connection speed that affects the speed with which you can download web sites or 'legal' files. In addition, if your ISP has many users connecting at the same time, you may see the bandwidth reduce to allow for the increased traffic. It's like a road. If there is no traffic, then you can travel fast. But if the road is busy your speed goes down.