Internet Problems through Windows - Not present in Ubuntu

I have a custom built PC with dual Ubuntu 64 bit and Windows 7 Ultimate 64 bit OS's. I would use the Ubuntu exclusively, except that I need to use Solidworks, AutoCAD, and a few other programs that are not easy to use through Ubuntu.

Whenever I'm in Windows, I have constant connectivity issues with the internet. It takes longer to load pages, and many pages do not load at all. I get the message telling me to uncheck the proxy server box - but it is already unchecked. Google Drive routinely will not work at all. Often when I choose a page that is an "app" from google I will get the message: "the app is unreachable" None of these are problems at all when I am logged into Ubuntu.

I seemed to have made some impact when I de-activated the inbound rules in firewall - so it may have something to do with that.

Please help! I have a quite capable computer and need to use Windows for some of the software I use - but I hate having to switch back and forth between OS's to reliably use the internet.

hey all - thanks for your suggestions and responses. I have tried all of these things and nothing worked. Internet takes forever to connect under windows, then often goes offline and other times appears to be functioning but won't allow certain sites. For example, youtube videos often take forever to start, then I get the message "an error occurred." Also, when I attempt to use the chrome "app" icon for gmail, or for my zoho mail account, I get the message "The app is currently unreachable." Often I get an error screen referring to the "DNS server" or telling me to uncheck the "use proxy server" box...but this is not checked. Completely disable firewall and antivirus...have the latest ethernet driver...problems occur through both Chrome and IE.

None of these things happen when the computer is booted into ubuntu. Same computer - same ethernet connection to broadband - but no problems at all with the Linux OS.