image size is locked on 'percentage' and cannot be reset to pixels.

Having a similar issue now - August 2024 & I have a solution (Mac version & on Adobe Creative Cloud).

I opened an image that had been sized incorrectly for my purpose but all dimensions were locked & pixels wasn't even an option I could swap to as it is ghosted out in the drop down options:

FIX:

I ticked the "Resample" and was able to fix the issue - I could change dimensions, dpi and revert to pixels - phew!!

I have exactly the same problem (Win 10, PS Elements) so was anxious to see a solution.

Here about 5 years later and I awoke to the same problem and found a solution that worked for me. When you import the images have the properties panel open. Check convert to layers. That makes it a rasterized layer as well versus a smart object. Then it allow you to adjust the W and H as a measurement in the properties panel. Prior to converting to layers the w and h greyed in the properties panel. In the top toolbar it still reads as percentage but you can adjust with properties panel for sizing. Hope this of help to someone.

I know this is over two years later... and I'm not sure if you mean it reverts to percentage IMMEDIATELY immediately, or if it is the next time you open image size.  For me, it changes back to percentage everytime I reopen image size...  Very annoying.

So, if I open image size, change to Pixels, and then hold down Alt while I hit OK, then it seems to set Pixels as the new default.  

I am a total novice to photoshop but I had a sort of similar problem and maybe this will help someone? I had an issue (I have a Mac) where I could not resize the height of my photo without the length automatically adjusting to whatever the original ratio was.

I did not realize that the little chainlink to the left of the Width and Height boxes is actually a button.

When I clicked it, it finally allowed me to change the pixels independently of one another. 

I know almost nothing about Photoshop. But it might help!

I'm giving it one more go. Is the "Resample" box checked? It must be in order to choose pixels as unit.

Trevor asked this at the beginning, but denis never answered or acknowledged. It looked like he did, but he didn't:

It has probably been said already, but a reinstall will usually not fix this kind of problems. Wiping the Preferences is what it takes. Preferences are never touched with an uninstall/reinstall - they live separately under your user account (the "Users" folder).

Anytime my Adobe apps start acting funny, I go through this process and it fixes it most of the time.

Uninstall photoshop BUT make sure to choose the option “Yes, remove app preference”.

Once that process finishes, start the installation process and look into the “Advanced Options”. Uncheck “Import previous settings and preferences” and choose to “Remove old versions”.

Hope you find this helpful!

Sebastian

Maybe try resetting your Photoshop preferences, which you can find under the General tab in Photoshop preferences.