A day ago i was able to log into the client and chose to play Witcher 3 but now it says someone else is using it and cant get into my client. I have already changed my password in case someone else is using it. I have also looked on start task manager to see if it is already running.

Are you sure Galaxy process isn't running in the background? I can log in on two different PC's at the same time without any problems..

hit ctrl + shiot + esc at the same time, task manager should open, search for GalaxyClient.exe in the processes tab.

Dont see anything with "GOG Galaxy" in it.

hmm.. That's interesting, did you try restarting your machine?

Found it but its not letting me close down the application!

Is it perhaps in use by another user on your computer? This was a long-standing flaw of the Steam client - it's possible that GOG's devs did the same thing that Valve's did.

There's only me on my PC.

Try with command line:
taskkill /im galaxyclient.exe /f

cant do it

Maybe you should try reinstalling the client.

I'll try that

k, please, try again with administrator privileges. Right click on Command Prompt icon and choose Run as administrator. If that doesn't help, try forced update:

%ALLUSERSPROFILE%\GOG.com\Galaxy\redists\galaxyupdater.exe /clientUpdatePath="%PROGRAMFILES(X86)%\GalaxyClient" /redistUpdatePath="%ALLUSERSPROFILE%\GOG.com\Galaxy\redists" /reportToService /updateClient /updateRedist

And one more thing to try before restarting pc. Run msconfig and find and uncheck galaxy in Startup tab.

Nope not working... always says someone else using it or cant force update.
Could i unistall it but if i did would it get rid of witcher 3??