I'm on Windows XP SP3 (yes it's ancient, but I require it for now)
Using the latest TCP Optimizer I have found 2 bugs.
Here is a picture for reference: http://imgur.com/a/OwKNG
1) The first bug outlined in red, happens whenever I use the custom settings and change the LAN Browsing speedup from Default to Optimized. The problem, is although it marks the file for deletion, after you restart the PC you can continually run TCP Optimizer and select this option over and over and the registry never stays deleted.
2) The second bug outlined in red, happens regardless of what settings are used. There is always a NULL registry for some reason. This did not occur in the previous version of the TCP Optimizer.
Thank you for your help, and thank you very much for this awesome program!