How to Remove an Old Outlook Profile in Windows 7:
1. Open the Windows Start Menu and left click Control Panel.
2. What you see here depends on how you have viewing Control Panel configured:
a. If you have Icon view, select Mail (32-bit)
b. If you have Category view, choose User Accounts and then Mail (32-bit).
3. Select “Show Profiles…”
4. Select and highlight the name of the profile you wish to remove. Most people will have two, Outlook and Google Apps, but more is possible and the names could be different. This is a destructive process, please make sure you want to lose all data in the highlighted profile before selecting “Remove”.
5. Confirm removing the profile by selecting “Yes”.
6. Alternative method: If you want to keep your profile data but skip the prompt when you start Outlook, you can alternatively select “Always use this profile” having it show your Google Apps profile, and hit OK. This preserves any data but allows Outlook to load without the prompt.