No, Quicken needs to be installed from installation media since there's more than just the Quicken folder in Program Files. There's a program called Zinstall that supposedly will copy a program from one Windows installation to another. Other posters have asked about it but I don't know if anyone has actually used it.
I'm afraid you cannot downlevel a Quicken data file in 2010 format to any older version's data format. It's just not compatible.
If you can't find the original 2010 installation CD or a saved downloaded installation file (have you looked in the Downloads folder?) your only way forward will be to purchase the current Quicken Home, Business and Rental Management version, either directly from quicken.com or from a reputable Internet retailer.
TANSTAAFL
I guess we all have different value equations…. for tracking personal finances or small business finances.
I happen to value Quicken for downloading and tracking ALL my finances…. at a yearly investment of $60 - ($5/mo)
Thank you, that tip helped solve this issue! I didn't even know about such programs for migrating programs, data, and even Windows user accounts to new computers. There is Zinstall, PCmover (apparently recommended by Intel and Microsoft), and PCTrans.
PCTrans even has a free/trial version which can transfer 5 programs before requiring a purchase. I gave it a try and it succeeded in migrated Quicken 2010 H&B to the new computer! Quicken 2010 shows up in Windows 10 Apps & features list (even showing the original 2010 installation date from the old computer), as well as in the Start menu. It seems to run fine, opened the QDF data file, made a backup, etc and didn't run into any issues so far.
What a relief!