I managed to get CCC functional on Windows 10 with a Radeon HD 4250 card. It's quite a long process, but meh it worked.
What I did:
Install the legacy drivers for my card. In my case it was the 13.9 version. Install it with compatibility mode for Windows 8 with admin rights (via properties, compatibility tab and make sure "Run as administrator" is ticked), it will complete and say it was successful. However, full functionality of CCC will still not be available, you'll most likely only see Power and Wi-Fi radio options. That's what I saw anyway.
After that, I went to Device Manager, clicked on Display Adapters > ATI Radeon HD 4250 > Update Driver.. > Browse my computer for installed software > Let me pick from a list of device drivers on my computer > Click "Have Disk.." and locate the legacy driver files.
The path for me was: C:\AMD\Support\13-9-legacy_vista_win7_64_dd_ccc\Packages\Drivers\Display - after hitting Display, you should see some .inf files appear. For me, I had several show up, so I selected whichever one worked for me (some gave errors for me). And then hit "next". Your screen will go blank and flash several times accompanied by some sounds. This is normal, wait for it to complete and then reboot. You should have full functionality of CCC again.
Bare in mind, the above was done on an HD 4250 card. I'm not sure if this will work for yours but it's worth a try. I'd also suggest to remove all currently installed AMD catalyst software before trying this method. This method didn't work for me at first but after removing all AMD catalyst software and then trying the above, it worked.
I still reverted back to Windows 7 though because even though I managed to fix overscan problems, I noticed the card wasn't performing as well as it was in Windows 7. Performance was worse and for a card that is already weak, reduced performance is not an option.
For overscan/underscan probem use AtiBBFix, hope it help you....