Hi garegin & welcome to sevenforums.
Don't try manual repair yet, SFCFix.exe will replace or most missing winsxs folder files from win7 DVD
Insert DVD run SFCFix.exe
If you don't have DVD you can download ISO from
Microsoft Download Center
You can't copy & past ISO (image file) with Windows copy & paste, you have to burn ISO disc. I use ImgBurn (free) I like free.
How to
burn win7 ISO to disk with ImgBurn.
Download
ImgBurn
If you don't have windows product key, it's in the registry in binary form (ones & zeros).
Run attached batch file. It will convert binary to alphanumeric and display it for you
I usually copy 5 characters, skip line on paper, copy 5 characters, etc. Then double/triple check that it matches. Easy to transpose characters or write C when it should have been G. (windows doesn't use A, 1 (one), or 0 (zero) in product key.
It's always prudent to have Win7 DVD, & do regular backups.
Should resolve your issue.
If you still have corrupt winsxs folder, if I don't have them, NoelDP most likely will, & can provide them to you. Place folder on desktop, run SFCFix.exe, it will find folder and replace.
If you mess with system files you have to take ownership.
I tried to restore ownership, (I've tried method by Brink, takeownership.reg & restoreownership.reg) Even though edit window shows TrustedInstaller has ownership, you can still copy, edit, delete file/folder.
That's exactly what viruses do.
