welcome back:)

Yay, good for you! =)

Thanks @all I have done all those things and then redownloaded steam and everything seams to be fine! thanks!

restart?^^ Maybe you have a broken version of idlem aster ? O.o Or try out to isntall steam new

lel

Had to rewright comment couple of times. =/

If the found solutions doesn't work, then, as I said, start with visual mods and AV protection, then check drivers(mb reinstall them), disable tweaks(and tweaker apps), try to revert all the changes you've made before all stopped working, and, if nothing helps, disable(or even uninstall) everything you've installed to get back as close to stock Win10(I assume you're running pre-Anniversary Update Win10, am I right?) as you can. If even this doesn't help, you definitely need those games and you have a lot of time, then you should consider resetting your Win10(be advised, resetting Windows will delete your personal data, so you should back it up beforehand).

In any event it's most definitely a software error rather than hardware issue(well, to be fair, you'd probably would got notifications all over the place if it was HW issue, or, which is even more likely, your OS just wouldn't run). So you should start looking in that direction. First of all - google this error. I found a video with possible solution, you should check it out: https://www.youtube.com/watch?v=nYW9emPr5Io or google some more.

@anfuerudo I will try that now

Why do I have the feeling that this has something to do with that visual mods? If not(well, it shouldn't be, but still), try switching off your antivirus - sometimes AV software can block apps from running properly.