connection problems

I am posting this message for a friend who cannot get online to do it herself.She has windows xp and her isp is Freeserve.
sometimes she can connect at a good speed but it does not last long . The dial up speed then gets slower and slower every time she tries to dial up. Then if she does get connected it may stay on only a few minutes. Her isp says her settings are ok her phone company says no problem with them.There is a problem somewhere any idea where.

 

It'd probably be a good idea for her to download, update and run either Spybot and Adaware, eliminate unnecessary startup items and give her system an early spring clean (uninstall unused software, purge the temporary files, scandisk and defragment).

http://www.safer-networking.org/

http://www.lavasoftusa.com/

http://www.sysinfo.org/startupinfo.php