ESET has a problem w/ opening many files.

[gito 0]

Hi there.
Yesterday, everything on my computer was running smooth and ok. Today, when I've started PC in the morning, a lot of things weren't working. For example - I can't play any videos on any browser, I can't run Steam. First I looked at HD and it said there's only 100gb space left. So I've cleaned big files by myself and let the CCleaner finish the work. Still can't play videos or/and run Steam. So I decided to run ESET Custom scan of C: and D: as administrator, but in log it says many folders on my can't be opened.
(I've tried - reseting PC, reseting router, browsers, reinstalling Steam)
-> Can't run any games on Steam or Steam itself, can't play any videos, ESET has problem opening files.
(I hope there isn't problem with requesting such general and non-eset focused issue fix)
Running on - Windows 10 (64bit) notebook, updated ESET Smart Security + 8gb ram, 1tb hdd, i5 2.40ghz
 

[gito 0]

+ wanted to mention that it was going fine until today's morning - it all happened when I've plugged in my headphones' USB.
I use them for a year or two now, everyday.

[Marcos 5,070]

It's normal that a lot of files cannot be scanned either because they are exclusively opened and used by the operating system or the user in whose account the scan is run does not have read permissions to the files.

[gito 0]

Thanks.
Btw. I've finished scan, restarted computer and left it be for 3 hours, all fine now.