Error with Warning! Legacy WGL is unable to select between different OpenGL versions Yesterday i was able to open the blender and use it normally; i updated to win10 3 days ago and was deleting and changing some stuffs in order to have a less slow pc and fix other problems with the double screen and other things. The thing is that now after finishing the "cleansing" i found that i can't open blender because of this:



But... before this message, i was having another issue while opening blender that was the one of the reason behind of this "cleansing". I had that annoying "LoadLibrary failed with error 87: The parameter is incorrect". After some research, i found that a way to solve it was by renaming the OpenGL driver "atig6pxx.dll" to "atig6pxx.dll.bak", and so i did that change and it worked, no more loadlibrary error, but... when i opened the Blender i got the message of not working/updated drivers, so, i went to the Driver Booster and updated 2 drivers, indeed, there were 2 drivers not updated after all this "cleansing"; i restarted the pc and after that... i opened the Blender and... BAM! another wild driver error message appears! I used Driver Booster to update the drivers, but it wasn't effective! (the drivers were already updated), so i decided to watch closely what was written in the cmd black screen, and found this damn message "Warning!  Legacy WGL is unable to select between different OpenGL versions" and i remembered the renaming process i did to solve the "loadlibrary failed error", and i asked myself "maybe that could be the problem", so, i went to the same folder, find that file and rename it back to it's original name, but guess what? it had its original name again! and i was like "okay, no problem... maybe that's the problem" so i decided to do the same like before, renaming it adding ".bak" and the end, but now this time i couldn't complete the task because i needed permission of "SYSTEM", and i was like, "oh god, why". So... that's it, That's the story.
Before this cleansing, i was able to open the Blender normally, but after that, i had all these issues i aforementioned in the story.

The Blender version i have is 2.79 (just in case).

Any suggestion on how i could fix this? ¡¡¡I HAVEN'T USED BLENDER IN 3 DAYS AT THIS POINT!1!1!
This is not a Blender question but I'll try to help you anyway.

Uninstall any display drivers you installed previously using DDU. Then just run a Windows update, that should load the most stable driver for you automatically. If that still doesn't work, go to amd.com, nvidia.com, or intel.com and find your driver from the Download/Support/Driver page.

A warning for the future, randomly renaming dlls is not a solution, it's a hack at best and is dangerous unless you understand what it's doing. In this case, you basically removed the OpenGL driver.