I got a new Lenovo laptop with Windows 10. I had read so many posts on various sites that Lotus Organizer 6.0 would not work on Windows 10, and most of the "solutions" suggested seemed very complicated and had poor results. I have no background in technology but found a way to get Organizer 6.0 installed and up and running. Fortunately, I had the install CD that came with my original purchase of Organizer back in 1997 or 98.
My new Lenovo laptop does not have an internal CD/DVD, so I used an LG Slim Portable DVD writer and downloaded VLC Media Player to run CDs/DVDs on my Windows 10 PC. I put the Organizer 6.0 CD in, and clicked on Install. (this is not an advertisement for LG or VLC...I'm only mentioning it as it was part of the process for how I got this to work).
On my old Windows 7 PC, I right clicked on the Organizer 6.0 icon, and saved the file to a jump drive.
I put the jump drive in the Windows 10 PC and copied the saved files to the Organizer 6.0 file I had just installed on the desktop.
It all worked, and I can now use my old Lotus Organizer with all my contact history and calendars on my Windows 10. ( I think I remembered the steps correctly -- it worked so quickly and easily I didn't think to write them down). Hope it works for you, as there is no better calendar/contact program available.