The problem here where ppl getting driver installation failed is caused because the new drivers included in the v3.50 folder don't seem to work. Use the older version drivers:
http://www.vodafone-star.com/images/vodastar_Driver.rar
I would also recommend vodafone-star webmaster to upload the newer version (3.50) updater to the official support download area (
http://www.vodafone-star.com/v810_download.html).