Installing XLL+ 7
Previous versions of XLL+
XLL+ 7 is not designed to run side-by-side with version 6 of XLL+. If you have XLL+ 6 installed on a machine, you will need to uninstall it before you can install XLL+ 7. If you are an existing user of XLL+ 6, and you wish to test XLL+ version 7, you should use a different computer, or set up a virtual machine.
64-bit Excel
Note that 64-bit Excel 2010, 2013 &2016 cannot co-exist on the same computer as any 32-bit version of Excel, including older versions of Excel (Excel 2007, 2003 etc).
You should also note that Microsoft Virtual PC does not support 64-bit operating systems, and cannot therefore be used to create a test machine for 64-bit Excel. On desktop machines, Oracle's VirtualBox can be used for this purpose.
Requirements
You must have administrative rights on the computer on which you install XLL+ 7.