Desktop internet speed very slow on Verizon fios

My sister's Windows 7 desktop would not stay connected to the Verizon fios modem. If I hook up to the modem and use Connectify for a hotspot and hook her desktop to that signal it hooks up and runs correctly. She has a D-link wireless adapter. I attempted to uninstall and reinstall the software. At the same time I would run the start up disk to install the driver. Microsoft would automatically install the adapter over it. I uninstalled the software and ran a Ethernet cable to it from my laptop. I let the Microsoft automatic driver install do it. It worked but there is a very slow internet speed. I tried the automatic trouble shooter and checked what I know how to in the internet sharing center. I have no idea what is up. Four other computers will hook up to the Verizon modem with 25/25mbps. Her desktop does it at less than 1/1mbps. I had to leave so I put Connectify on here laptop and she is getting here signal from the laptop. Can somebody give me an idea on what to check out so I can fix this issue.

 

Restart in safe mode. If speeds are good in safe mode then it's either a firewall setting/problem, spyware/virus, or other 3rd party software causing it.

Take care,
Shannon

 

Thanks for the reply. I will check it out this weekend.