I was very concerned about getting a new PC with Windows 11 (been running it on 10 till now) and moving my old UK version of Quicken XG 2004 across. I could not really get any comfort from the forums but decided to go ahead after researching possible alternatives should it go wrong! My experience was relatively straightforward, but here is my story! My new PC supplier mirrored all my data from the old PC across, so all my Quicken files back to 1998 were on my data hard drive (D). I also had the Application file 'QuickenUK2004R2' saved, that I believe was a patch or upgrade that came out later (mine is download dated 2016 - it is a big file of 30MB so I cannot attach, but a search should find it on the Web). I ran this no problem and when it asked if I was a new or old user, selected old and it then asks you for the Qdata file you want to use. I located it on 'D' but it came back that it could not run. I also tried some of the older data files with same result. Being a bit worried now, I then put all the Quicken files on my old PC onto a stick drive and then selected Qdata from it and hey presto, it worked! Everything loaded correctly, and the Qdata file loaded into my 'C' drive under 'program files (X86)\Quicken, where the program files are located. I then did a back-up to my 'D' drive but when I tried to then open it to test it, it wouldnt open - no problem doing that on Windows 10. For some reason (computer buffs may know why) it won't accept the files from the data hard drive 'D'. I then open each of the older files in turn from the stick drive and they all opened fine and then I saved them to the same place on the 'C' drive where I can now move easily between the different years should I wish to. Should my 'C' drive get corrupted or fail in future, the files are still safely on 'D', so I would just have to do the same again and load them from a stick drive.
I hope that makes sense and gives others who may be frightened to upgrade to Windows 11, as I was, some comfort!