I have recently purchased a Dell Inspiron 15X laptop with Windows 7 after upgrading from a Dell inspiron with Vista Business.
I have had a 3 mobile dongle for 2 years now with minimum issue's. However, after starting back at work & attempting to use my dongle with my new laptop, although I could surf the net perfectly fine, whenever I tried to access ANY email be it Live mail, Google-mail or through the First Class business software used by my employer, the laptop COMPLETELY FROZE within 2/3 mins of logging on and the only option left to me was to manually switch it off. After wasting over an hour on the phone to a useless "help line member" who told me that although my PC ran fine at all other times except when their dongle was plugged in, that my operating system was at fault.
I then "took to forums" which is perhaps what I should have done in the first place & collated several of the issues I read about & applied their fixes to my issue.
After many hours of "messing about" I turned off ALL network sharing options and homegroup sharing options in the Network & Sharing Centre & it worked!!
Although I can now access all of my mail I cannot add my laptop to a network using my 3 Dongle so if anyone else has any other ways of solving this issue then I would be please to hear it!
Cazz