First, it looks like Adobe CS5 applications have not been updated for High Sierra, and thus are 'problematic' with High Sierra. This link discusses all Adobe apps and High Sierra: Secondly, if you have a Time Machine backup, it is not bootable, but based on this: you can do a complete restore of the Mac OS (Yosemite), all your applications, files, settings, etc. However, if your new Mac has an SSD, and already has High Sierra installed, that SSD will be formatted as APFS, and Yosemite is not compatible with APFS. But, using Disk Utility, you should be able to partition the drive, and for that second (empty) partition, Erase and Format it as Mac OS Extended (Journaled). What I am unsure of is whether using the High Sierra version of the Recovery HD partition (that is what that link is talking about above) will work. I suspect it will, but maybe someone else with more expertise (Cory, we need you!) can clarify this.

I have upgraded my test Mac to the release version of High Sierra. Based on some quick tests I did, Adobe applications before CS6 do not run as smoothly as they did in earlier versions of macOS/OS X. The CS3–CS 5 applications seem particularly risky to me. There are more hoops to jump through to. As of September 25, 2017, macOS 10.13 High Sierra is publicly available for all Mac users to install. Adobe has discovered some compatibility issues listed below. If you encounter other issues using InDesign CC for Mac, send feedback to InDesign User Voice.

I myself would go about this differently, but to do that, you would need a bootable backup/clone created by either SuperDuper! (I use it) or Carbon Copy Cloner.

Hello, Adobe CS5 apps are definitely not officially compatible with High Sierra. There are reports of them working, albeit with some issues. CS5 was originally released in 2010, with the latest version, 5.5, in 2011.

The original versions of OS X that it was designed for were 10.5/10.6. Because of that, I wouldn't expect or rely on it to work well. If you buy a new/current Mac, unfortunately it will not support Yosemite, so there isn't the possibility of setting up a dual-boot/partition to run it along side High Sierra to allow use of CS5. Normally, when Mac models are released, they can only support the version of OS X they ship with and newer. If you are buying a more current used Mac, it would depend on the model. Hope that helps a bit, C.

I just did the same thing but with CS6. Unfortunately I had a site license for CS6 from a previous job (it's not in my name). I made what I believe was a big mistake by signing up for iCloud.

All applications and data were transferred to my new iMac by the shop where I bought it. When I went to use Photoshop (after signing up for iCloud) I got a prompt asking if I was ready to start my free trial period of Photoshop.? I got totally locked out of my own software and not sure but think it had something to do with iCloud.

I still have my old iMac and now just use it for CS6 (I don't even hook it up to the Internet). I am told CS6 should work on High Sierra but with the next new OS no software will work that is not 64 bit and will require ALL new software. I also recently got a new Mac using High Sierra replacing my older system using Yosemite (see previous post in this thread) and had Creative Suite for CS6. I found that you must have the original serial number to open CS6 on the High Sierra OS.

The first time you attempt to open any CS6 apps you will be prompted to begin your 'free trial' for software you already own. There is, however, a button on that window to register your software. I thought that was for people with new software but I used it and input my original serial number and everything opened fine.

My CS6 software as well as ALL my software works roughly the same as my old Mac maybe even slower. That is because High Sierra functions on 32 bit software, the old 16 bit software works with High Sierra but same speed or slower.

My tech Mac guy tells me High Sierra is the last Mac OS that will run 16 bit software at all and with the next upgrade nothing except 32 bit software will run. Mac bootable usb windows 10.