Why do I have so many explorer processes running

Have you applied something like this? Try to change it to 0.

Code:

rem 1 - Launch folder windows in a separate process
reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced" /v "SeparateProcess" /t REG_DWORD /d "1" /f

Additionally you can also check:

Code:

reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer" /v "DesktopProcess" /t REG_DWORD /d "0" /f

0 - All of the components of Windows Explorer run a single process
1 - All instances of Windows Explorer run in one process and the Desktop and Taskbar run in a separate process

going back as far as windows 3x Explorer.exe has always been a major component part of windows, in many ways it was considered to be the Windows executable,

The load is now being shifted onto svchost.exe which runs many instances concurrently, I have a few things running in background and foreground and have more than 75 instances of svchost.exe running, (svchost.exe used to be shown for groups of processes but due in part due to hiding malware in the process groups it's now shown individually, which allows the user to end a process that is causing problems without crashing other processes )

The explorer.exe process is still used by some older processes so will show at times even when it's main GUI component is not in use

The thing to watch with both of these executables is a sudden change in their usage "costs" - if explorer.exe or svchost.exe starts to use a lot more processor cycles or system memory then use something such as Process explorer from Microsoft's Sysinternals suite to see what is actually calling the process giving concern