Hi drvipuldon, It appears that the scanner is not compatible with Windows 7. You can poke around yourself at the software download page on UMAX.com http://www.umax.com/download/index.jsp
I went to the UMAX home support page http://www.umax.com/download/index.jsp and did not see any Windows 7 or Vista drivers listed for the UMAX Astra 4100. You can check for yourself at the provided link.
Hi drvipuldon, It appears that the scanner is not compatible with Windows 7. You can poke around yourself at the software download page on UMAX.com http://www.umax.com/download/index.jsp
If there isn't a W7 compatible driver, try installing the XP driver manually via the control panel, i.e. add new hardware and see if that gets it going.