In the Property List for the UserForm, Find the property:
ShowModal
And set it to False
This will make your UserForm "modeless." When the UserForm is modeless, the user can view other forms or windows without closing the UserForm.
Note If you attempt to open a UserForm that has a ShowModal property in Microsoft Office 97, you get a run-time error because Office 97 only displays modal UserForms. Office 97 ignores the ShowModal property and displays the UserForm modally. So for you to have this option you must have a newer version of Excel!