1. If your go into Microsoft Office – at some point you will get a message dialogue from Outlook to say that it is not the default email client.
2. If you click ‘No’ to the option 'Do you want this to be the default email client?' There should be a checkbox on “Do not ask me this again”
3. If you follow the above it will not revert back to Outlook again.
It sounds like you need to make Gmail your default email client - so that any email links you click inside your CRM account will open up your Gmail email client and not Outlook.
You can set up Gmail to be your default email client by following the instructions contained in this link
We have also done some Google searching and have found this link below where someone has addressed the issue of Outlook opening up as the default on Windows XP when they want to set up Gmail as the default email client - there is some advice contained in this link about how to go about setting this up on your computer:
http://www.techfleece.com/ 2011/02/18/how-to-make-gmail- your-default-email-account-in- windows-xp-and-windows-7/
Unfortunately as its not a CRM issue we can only advise you what we have found from our Google searching and information from Gmail themselves.