Hello PoL users, In order to combat some of the issues related to download.microsoft.com, I'll write a short guide. This will require a bit of knowledge on how PoL works, not much, but this is an issue the devs should handle immediately so that the uninitiated can have an easier time.
So to do this with Photoshop, we must first look at the components listed in the install code over at https://www.playonlinux.com/en/app-2316-Adobe_Photoshop_CS6.html
POL_Call
POL_Install_AdobeAir
POL_Call
POL_Install_atmlib
POL_Call
POL_Install_gdiplus
POL_Call
POL_Install_msxml3
POL_Call
POL_Install_msxml6
POL_Call
POL_Install_vcrun2005
POL_Call
POL_Install_vcrun2008
POL_Call
POL_Install_vcrun2010
POL_Call
POL_Install_corefonts
POL_Call
POL_Install_tahoma2
POL_Call
POL_Install_FontsSmoothRGB
This list here provides a the components we need to install through the "install components" tab of a virtual drive. Create a virtual drive with the wine version 1.7.46-staging for x86. Go one by one, installing these (in the case of corefonts, it is called Microsoft Core Fonts) and if you run into a download error as we've described above, write down the link. To get the original files, we can use the Internet Archive's Wayback Machine to get them! In your browser type the links as so into the URLbar:
http://web.archive.org/[URL GOES HERE]
You should (and in the case of the missing files here, they will) give you a download to the required installers. It is worth noting that the script also tells us to set the OS to Windows 7, so after you've run all the installers before the Photoshop installation, set it to windows 7. Now, to get down to the installation select the new virtual drive in the config window, go to the Miscellaneous tab and "Run a .exe in this virtual drive" which will be your installation EXE. Install it, and you've done it! Now you should check out the General tab and make a new shortcut to the EXE (PhotoshopCS6.exe, I believe).
A note about the GDIPLUS installer: It will ask you to extract, extract it into My Computer > C: > Windows > System32.
A note about TOR: I have been able to download these through TOR in the past but using wayback machine seems a bit easier.
That's it! This worked for me, I cannot guarantee it to anyone else. For convenience, both Najodleglejszy's and others, here is a link with the installers that were missing (for me at the time of writing). https://u.pomf.is/bydbem.zip