Via CD/USB or from windowsiso? Which version is that? The one got after uptade is 1809.
Use my guide: https://forum.infinitymu.net/showthread.php?111275-Guide-Windows-Build-Revert
Pick 1709 build.
Turn ur internet off while the windows is installing.
Download all the drivers for ur pc and keep them on a usb. And install them on the new os u just installed but without internet connection and windows update disabled.
It fits ur Windows 10 Pro.
Version order: 1709,1803,1809.
You can download from here also: https://www.microsoft.com/en-us/software-download/windows10ISO
April update is 1803 version.
What about if I'll keep ISO file on PC, off my net and install it w/o usb? USB, it's for keep files/apps safe? April version ruins smoothly?
If u did exactly like i said in page 1 u should not have any problems.
How did u update ur drivers? Without internet and windows update disabled?
Did you adjust your video card settings to run on preformance.
Did you changed the power settings to high preformance.
Closed running background programs by going to settings> privacy background apps click off.