Unfortunately, Microtek doesn't support the V6UPL for any Windows OS beyond XP. The drivers are available here: http://support.microtek.com/downloads/bycategory.phtml?slct_tbl=1&slct_mdl=2
What version of Windows 7 are you running? Click Start > Control Panel > System and Security > System. If the version name ends with x64, you have the 64-bit version; otherwise you have the 32-bit version.
If you have the 32-bit version, try using the driver from the above site with the compatibility mode. Right click on the .exe file and choose Properties. Then select the compatibility tab. Set the program to always run in the compatibility mode for XP. Then right click again and choose Run as administrator. (You may need to disconnect the data cable and uninstall the Unknown device before trying to install the XP driver).
This will probably not work for Win7 x64. There are workarounds that you can use. You need to connect the scanner to a computer running an older version of Windows. This can be a physical second computer, a dual boot computer or a computer running a virtual version of the older OS. If you have Win7 Pro or Ultimate, or upgrade to one of those versions, you can have a virtual version of XP for free. Download and install Virtual PC and XP mode (in order) from Microsoft. Then install the XP scanner driver in the XP mode program as if that is the only computer running. The only issue is that you can't share files or your printer between the virtual and real computer at the same time. You will be prompted to uninstall the printer if you try to install it on both machines. You can put files on external media to share them. Other virtual computer programs are Parallels and VMWare. However, you need a licensed version of the older Windows OS to use any of the other alternatives.
I hope this helps.