Windows 7 - USB stick problem - error 31

Hi all,
I have problem with my Huawei K3715 dongle. It won't let me connect to the internet, I keep getting RAS error code 31:
Mobile connection not possible.

- Set your current mobile device as the default
device in the 'Manage Devices' view
- Ensure that no other programs are using your
mobile device and try again in a short while
- Delete the device in the 'Manage Devices' view,
add it back again, and then try connecting.

If this error persists, please contact Support
at your mobile network operator.

Support information:
RAS error code 31

It's working perfectly okay on XP (SP3), but seems to have serious problems with my Windows 7, no matter how many times I uninstalled and installed the drivers. Updated firmware, updated software, performed system restore, nothing worked. I shall give up very soon, throwing the darn thing out the window I really wouldn't want to make a clean install, it would take ages to transfer back everything to my pc. Really hoping that someone has a solution to this problem

Double check if you have the right drivers for Windows 7 32 bit ( may called x86).
Unlike softwares, drivers are made for each windows edition.

Hi! murron, welcome to 7F

Your dilemma sounds similar to this one where you have tried everything: usb stick detection problem

Go to this post #4 by Bill2 in the same thread, and use the link provided there: usb stick detection problem

It may be as taupuz the OP was having trouble with drive letters, yours may be similar.

Follow these instructions provided to clear the conflict, and see if it helps your situation: Cruzer flash drive could not be detected due to drive letter conflict

The fix is the same even if you do not have a Cruzer drive.

Hello murron and welcome to Seven Forums.

Part of the problem might be the age of the dongle (when it was manufactured by Huawei.) They may not have upgraded their drivers to work with Windows 7. It's possible they might have a Vista driver that would work in compatibility mode although I didn't see one.

Have you contacted their support team to see if they actually have a driver for 7?

Technical Support - Welcome to Huawei.com

Thanks for the responses, everyone.
Anak, although I had no conflicting drive letters, I tried the link you provided said. No success
Marsmimar, there is no such thing as support team for Huawei. I have found a Win 7 driver in a 2 year old thread (their forum has closed down since), but it didn't help me either.

Have you seen this link? There seems to be two solutions that may work. Huawei E220 driver for Windows 7 Read the whole thread.
Of course you would have to substitute the 3715 wherever it says 220.

I did not go into exploring the links that kabous0834 or driekwartappel provided in the above link, but there may be firmware for your 3715 listed at those links.