I was having the same problem with Alcatel Lucent Cellpipe modem with Vista. But now its working fine on my system. Just follow the simple steps below and you can get ur internet up and running.
1. Go to www.etisalat.ae
> Customer Support > Downloads and Useful links > Modem drivers> Alcatel Lucent 20 A
2. Download and save the file on your desktop.
3. Extract all files.
4. Go to your computer's C drive > Windows > System32.
5. Copy the file "GsiDi32.dll" (DSL installer) and paste it in the folder of the downloaded modem driver. If it asks to replace, click on Replace the file.
6. Connect your modem to the computer and make sure the USB light is on.
7. Ignore the Found new hardware wizard and go to the folder where you saved the downloaded driver files.
8. Run setup.exe.
9. If it gives a dialog box of Missing Entry, just click OK and proceed with the instructions of the setup.
10. Your inetrnet will work fine once you enter your username and pwd.
Hope it works for you all.
Best of luck..