The Kernel32.dll file handles memory management, input/output operations, and interrupts. When you start Windows, Kernel32.dll is loaded into a protected memory space so other programs don’t attempt to use the same space in memory to run their operations.

Kernel32.dll error messages may appear when Windows starts, a program is opened, a program is running, a program [...]

DLL (Dynamic Link Library) is a collection of small programs, small programs which contain commands and/or data that are common to a certain task, the executable program (EXE) that is running. The DLL lets the executable communicate with a specific device such as a printer or may contain source code to do particular functions.

The advantage [...]

A missing or corrupted DLL file library is a very common computer problem, and the causes of this kind of problems are:

A recent uninstalled program
A recent program has overwritten a .dll file
DLL file was deleted accidentally
File was corrupted
Hardware issues are causing dll errors.

A few examples how you can fix the error:
Missing or Corrupt Windows DLL [...]