When you ask a question you need to provide some basic information
-Forum quick start https://forums.adobe.com/docs/DOC-5601
Mac or Windows, and EXACTLY which version of the operating system?
Recent Mac AND Windows operating systems have been known to cause "odd" problems
Are you using a computer Administrator account with full read/write permission?
Adobe Photoshop CS4 Extended (64 Bit) Using full read/write Admin acct.
I apologize for being a bit pc/program/tech clueless.
As far as I know, CS4 is not 64bit... 64bit programs did not start until CS5
Owners of old programs simply have problems with Windows 10... none of which is Adobe's fault... Adobe did not change your old program to make it stop working... Microsoft changed their operating system and THAT is why your old program won't work, not because of anything Adobe did... Also... every time Microsoft issues a Win10 update, there is the risk that an old program that HAS been working after the initial Win10 upgrade will STOP working... bottom line, old programs require a matching old operating system
An idea that MAY work to install and/or run old programs in Windows 10... works for some, not for others
-RIGHT click the program icon or EXE and select a compatibility mode in the pop up option window
-or Run as Administrator http://forums.adobe.com/thread/969395 to assign FULL Windows permissions may help... says Encore, but sometimes required for ALL Adobe programs (this is NOT the same as using an Administrator account)
-or more on permissions https://forums.adobe.com/thread/2293598
NOTE - Win10 anniversary update version 1607 has caused MAJOR problems with old programs, so the above may not work
Thank you for your reply. I will look into your suggestions. I did try running as an Admin and it didn't help, I will search further into your "Full Window permission" suggestion.
It IS a 64 bit, that was copied/pasted into my comment.
Thank you again for your quick response.