Explorer is very slow after connecting external HDD

Recently I've got a new laptop with SSD drive. However, sometimes when I'm connecting external HDD to this laptop, explorer seems to work painfully slow, even when browsing folders on my internal SSD. Indexing on external HDD is turned off. Problem does not exist when I'll restart my computer with external HDD plugged in.

Do you have any ideas what might be causing the problem?

Solution 1:

You have several issues.

1.) the csrss.exe usage is caused by a bug starting with the Update KB2850851. This updates the Win32k.sys driver and this driver causes a high CPU usage while detecting a monitor and the rotation state:

MS is currently investigating this issue. If this is urgent for you, phone the support and remove the Update as a workaround.

2.) the system/kernel usage is caused by the APCI.sys driver which often happens when the CPU overheats (because of the other issue).

3.) the svchost.exe usage comes from Avast (aswSnx.sys):