[Help] Need UMAX Astra 6850 scanner driver  

Welcome to Seven Forums. I checked the Umax site and they didn't list the 6850. The closest I could find was the 6700, and they only offer XP drivers which would require installation in compatibility mode Compatibility Mode XP. UMAX.com Download Software So I tried based on your VM page Umax support UK and about all I could find is a contact page. Contact UMAX Which you might want to give them a email and see if the scanner is even compatible with Windows Seven or if they plan on putting out even vista drivers for it.
Do you have the original installation cd for the scanner? If so you might want to try to place them in a folder or on you desktop, right click the setup .exe file> click properties>compatibility>check the box run in compatibility mode and select XP from the drop down menu>then run as administrator.
I'm thinking though this is not going to be an easy nut to crack.
No offence but I would try and stay away from 3rd party driver programs that you need to pay to use. As in the instance above, when you click on the Umax 6850 driver download it will scan your system then ask you to register it then you have to pay. JMO. Good luck.Fabe