After using a tweak program, I now cannot connect to the internet. I
have tried rebooting etc.

Well then how are you posting on Google Answers if you have no internet? hehe 

Sorry, had to say it.

Umm, well, you could use your system restore option in Windows XP
which allows you to go back to a particular point.

Go here and Microsoft will tell you how to do it ...

http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q306084

You could try and uninstall the program you used or try using that
same problem and seeing if it offers a restore option or a option to
go back to the way you were.

My experience with those programs are that they tweak mainly your
registry, so even if you did uninstall it, it most likely won't fix
the problem your having. Either contact the person or company who
wrote the program or use my other idea with the system restore.

One last comment.  Donwload this program and it offers an option to
restore Windows XP's original registry settings (when it comes to TCP
tweaking).

http://www.speedguide.net/files/TCPOptimizer.exe

With my slow notebook.

System restore also does not work.

I used FreshDevices FreshUi and what a mistake that was! No BIG
WARNINGS ABOUT WHAT EFFECT THE CHANGES MAY CAUSE. I looked back and
cannot see what I chanaged.

If try  TCP Optomizer if offers you an option to reset the original
Windows XP TCP settings (the ones that Windows puts in my default). 
It may work.  I would give it a try.


http://www.speedguide.net/files/TCPOptimizer.exe