I'm sorry if this isn't the place but I just got a new Laptop after my old one broken down and I tried to install Gwent on GOG Galaxy. I got the Witcher: enhanced edition with it for free and I was so excited to play it because I never really owned a PC with a working Keyboard. It was gonna be my first time so I installed it, all to one folder like it was set (I didn't change anything) and when it finished installing it said it's missing a file I dunno exactly which one but it said "dll" at the end. It said to reinstall the program so I reinstalled the Witcher, same problem. Should I reinstall the whole thing?? GOG Galaxy??

You need to install DirectX 9.0C
Make a new temporary folder on your desktop.
Go here http://www.microsoft.com/en-us/download/details.aspx?id=8109 And download the June 2010 runtimes to the temporary folder .
Disable your antivirus software.
Then scroll down and run DXSETUP.exe (see pic)
When it says, Installation Complete, you can delete the temporary folder, and re-enable your antivirus software.

will it mess with my pc? i'm windows 10 i can delete the new folder with all the files after installing the DXSETUP right? and thr June10 file too? i can just delete them and start W1 safely without them no?

Yes, delete the new folder and everything in it.