Corrupt system files issues.

Hello.
2 weeks ago i turned my pc on and then left the room and came back 10 mins later and it was showing chkdsk task so i left and returned 15 mins later and it was still checking but it had errors listed that it had found. The chkdsk was not scheduled or the pc shut down wrongly before i started it it up. The only thing was i went to print 2 letters and an box came up with something about .dll error and i may have to reinstall the printer but the i was able to print the letters ok.
The chkdsk finished and there were no bad clusters but missing system files and other things but i cant remeber what.
After the the pc finished booting up there were a lot of errors in event log but no critical ones. I ran mse for virus and that was ok, done malwarebytes and superanti and they all came back ok.
I then did SFC and that showed up errors so i done seagate tools and ran all the test and it showed no HD errors. I then did a restore to the day before and there were still system file errors.
Next i deleted all the things on the pc that were not critical and ran SFC and chkdsk again and i still had errors like shadowvolume or something like that so i thought the hard disk was on its way out and i got another new 160gb drive and cloned it and then swapped drives and it booted up ok but the errors are still there so it maybe the sytem files are corrupt after all.
Last thing is i did a Windows 7 update about 2 days before all this happened so maybe connected or not.

Thanks.

Did you run sfc /scannow?

To fix you can reinstall. It will keep your configuration and data.
- Backup your data.
- If your Installation disk isn't SP1 download it from here Microsoft Windows and Office ISO Download Tool
- You don't need to burn a DVD. You can extract the iso files to a folder and run setup from there.
- Or, from inside Windows, run setup from your installation disk.
For the updates: MS releases SP2 for Windows 7

Thank you Megahertz07 for replying.

I have ran SFC a few times when it happened and i have done it again about 10 mins ago.
I have a CBS log file hopefully attatched in this post.
The one thing have remembered after doing the SFC is that GXW control panel keeps alerting me to possible Windows 10 app being installed and it has not done that before.
If i do a reinstall will it be exactly the same as before the problems like all my icons/shortcuts on the on the desktop and all the settings the same as now or will i have to redo all of them?

Thanks.

If you do a reinstall it will be exactly the same as before the problems like all your icons/shortcuts on the on the desktop and all the settings the will be the same as now.
Remember: You have to launch setup under windows and NOT from booting the installation disk.
It's an "upgrade" to same version.