My Windows 10 File Explorer is getting slower and slower (not for copy purposes but with file openings).
My PC is relatively fast: CPU i7-6700, 16 GB RAM, several internal SSDs, several NAS devices with Gigabit Ethernet connections. My Windows is up to date: Windows 10 Pro 1809 Build 17763.379, I only run Defender as antivirus app.
At first I thought this is because I have a slows NAS. I updated to a new NAS, it is the same. Now I made a test with differrent filey types TXT, RFT and DOC, all very small files. I even changed the associated programms to Wordpad for txt and rtf and Textmaker for doc. I copied the folder with these files to an SSD in my PC, even to the boot partition. But is is always the same: Some files open instantly, some take some 20 seconds. Not always the same files but mostly with RTFs and Wordpad.
The files are small, some very small, chosen randomly:
icons.doc 24KB, license.rft 1KB, Macrium SNR.txt 0KB, Recovers.txt 0KB, Test.rtf 1KB, Test2.rtf 1KB.
I changed the default apps because I thought, that MS Word might be the culprit, but it was not as the errant opening times remain.
The same behaviour with small (up to 400KB) JPG files. In some folders they open instantly in others it takes 20 sec. Even reopening after closing the app (Irvanview) takes another 20 sec.
The same with MP3 and VLC.
Meanwhile I made an Windows 10 1809 in place upgrade. It did not help.
My internal drives are still ok and have between 12 and 29% free space.
I ran several antivirus apps from an external Windows SSD. They only complained about IOBits Advanced System Care and found no malicious software.