pithydoug Loc: Catskill Mountains, NY

Poppycock. Been using Win for years and years. I have found win 10 flawless and I use tons of SUPPORTED programs. Stay on top of the service stream, this way if you have an issue you call and get an answer. Load you machine with bandit aps and you take your chances.

Once you start installing quasi supported programs, or trying to use programs 3 or 4 releases old, and/or not take your updates you paint yourself into a corner and then blame the OS.

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

I'm not familiar with Macs, but if Macs support dual boot and/or virtualization it should be theoretically possible.

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

I use a lot of unsupported (old) software on W10 also. Very few would not work. Some needed some device driver research etc. but could be made to work. The majority are just fine. Many people consider W10 to be the best MS ever. It is highly configurable. My desktop looks and behaves much like W7.

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

The simple answer is yes. Windows supports dual boot functionality, so for example, you could have Windows 10 and Windows 7 on the same machine. You just select which you want at boot time. It uses more disk space, but it works very well. I ran a dual boot W7 / W10 system for two months when W10 came out until I was confident enough to switch.

W10 compatibility modes could address the OP's problem or a virtualized approach to run multiple OS instances.

Or simply bite the bullet and move to Adobe CC.

cameraf4 Loc: Delaware

The problem may be that sirsnapalot's older version of PS may not "play nicely" with a 64bit computer OS. Happened to me, too, so I bought a refurbished PC with Windows XP for about $100. Only use it for photo work, not connected to the net, works fine with "old" apps (like my ancient version of PS) and scanners, etc.

mainshipper Loc: Hernando, Florida

Are you talking about Version 5.5 or CS5 as I think there is a big difference? The first version of PS that I owned was Version 3.5 and that was in the early 90s. For several years they released versions labeled X.X and then used the CS designation when they started branding their core graphics products as CS (Creative Suite) starting with just the name Photoshop CS. Here's more info on the version history https://en.wikipedia.org/wiki/Adobe_Photoshop_version_history.

If indeed you are running Photoshop 5.5 (circa 1999) then I would assume that you may have compatibility issues at some point in time. Windows 10 is a very stable version of Windows and will tolerate a lot of outdated software but maybe not from 18 years ago.

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

Sometimes those are device driver or .dll issues. With research and work they can somtimes be solved. I had that problem with Adobe CS3 and moving from W XP to W7 64. Once I found the appropriate .dll everything was fine.

Sirsnapalot Loc: Hammond, Louisiana

Good idea, thanks!

Cape Coral Joel

Try compatibility mode as mainshipper suggested. Just right click on the program select compatibility and select the software you were using ie windows 8.1. It doesn't always work but it's worth a try.

DaveMM Loc: Port Elizabeth, South Africa

I run a 2009, free for non-commercial use, CAD program that only runs on XP. I have installed it in Win 7 and Win 10 in compatibility mode and it runs very well. These are the notes I made when I installed in Win 7, but the same process works on Win 10 (note this is for a downloaded file - with Photoshop from a disc, Step 1 will not apply, and Step 2 will start with right clicking on the installation file on the disc):

Install ProgeCAD 2009 Smart on Win7 Home Premium
NB. This must be done in Administrator mode, not in a limited user account.
1 Save the ProgCAD 2009 Smart download file to your desktop.
2 Right Click on the file once download is completed.
A Select "Troubleshoot Compatibility"
B A Wizard will launch, Select "Troubleshoot Program" (manual troubleshooting ignoring recommended settings option)
C Select "The program worked in an earlier version of Windows but won't install or run now"
D Select "Windows XP (Service Pack 3)"
E Click "NEXT"
F DO NOT use the "Start Program" button that appears in the wizard
G Instead grab the top bar of the wizard window and drag it out of the way off to the side left open.
3 Right Click on the downloaded install program on your desktop
A Select “Run as Administrator”
B The main program will now successfully install on your system with two exceptions
a Error message about unsuccessful install of .jpg printer
b Error message about unsuccessful install of .pdf printer
4 Once install has been successfully completed then close the compatibility wizard you dragged off to the side by clicking on the red close box in the upper right hand corner NOT the “Next” or “Cancel” buttons.

Hopefully Photoshop will now run.

lamiaceae Loc: San Luis Obispo County, CA

You do mean Ps CS5.5 and not "plain" 5.5, right? That (Ps 5.5) was for what, Windows 98? Did you deactivate or unregister it from your old computer before trying to use it with Win 10? Adobe lets you use a given product on only 3 devises at a time. So you need to totally UN-associate it from previous system(s) before trying to add another fourth one. There are lots of reasons why old aps that were written for say Win 7 don't work on Win 10. Stop blaming windows for everything, all my programs and applications work fine with Windows 10. And if you don't have the installation discs, move on. Yes, and I'm using Photoshop CS6.

lamiaceae Loc: San Luis Obispo County, CA

"Version 5.5 or CS5.5", huge difference!

lamiaceae Loc: San Luis Obispo County, CA

EXACTLY!

Tet68survivor Loc: Pomfret Center CT

I have found, with some of my old, expensive, radio communications programs, that if I installed them in the "root" directory instead of the x86 program area, Win 10 recognized them and they worked just fine, just don't expect Win 10 to update them to the latest and greatest version!

Dngallagher Loc: Wilmington De.

Macs will easily boot from pretty much any connected drive that has a bootable Apple OS on it - just select it at boot time till you want to change it - you can easily have Yosemite on an external and boot with it, or boot to Sierra on your internal.

You can also set up BOOTCAMP to run a dual partition - one for Mac and one for Windows almost automatically. That is rather drastic though in my opinion.

You can also use Parallels or VMWARE Fusion to set up a Virtual Machine to run under OS X fairly easily to run any number of operating systems under OS X, and for a no cost Virtual Experience, there is always Virtual Box, free for the downloading that will let you run Windows, Linux or a DOS operating system on your Mac within OS X.

I suspect that the larger issue with the OP is simply running older software on a newer OS - as security changes, as things change in the OS, as programming calls are no longer supported by the newer OS, older programs will cease to function in some or all ways. In my opinion, it is always best to remain current from the OS down to the main software in use - I update my OS as soon as it is available, never had any issues worth worrying about, I use software that is either free or on a subscription basis, so I keep the programs all updated as well - every update/upgrade.

When High Sierra is available for general use - Apple gives it away for free, and it will be on my Mac within a day or two. and I am confidant that my Adobe CC subscription will be ready when it is. EMail will be part of the OS, the Web browser will be part of the OS, LibreOffice will either work fine, or be updated for High Sierra - the remaining apps are just apps that get updated for the OS as well.