While running the Services.msc
GUI offers the ability to manually set a Windows service start type to Automatic, Automatic (Delayed start), Manual, or Disabled, the configuration of services is stored in a Registry tree that can be configured via the command shell and registry editor.
When using sc config
or regedit
, the options for service start type are 0
, 1
, 2
, 3
, and 4
, which correspond to Boot
, System
, Automatic
, Manual
, and Disabled
. Boot and System are now configurable options. Changing an arbitrary service's start value data to 0
does make Services.msc reflect "Boot" in the Startup Type column (although attempting to edit that service startup type through the GUI only provides the regular four options).
It seems that Boot and System are useful additional options, yet apparently few or none of the default Windows services take advantage of it - not even Windows components that seem pretty integral like Power, Windows Defender Advanced Threat Protection, or Cryptographic Services.
So my question(s) are:
- Is it safe to set services to start at
Boot
orSystem
if they are desired to run even earlier thanAutomatic
services? - Will doing so cause system instability? (And if the answer is "it depends," please point to some documentation that provides a rationale, and ideally that could be used to determine which services, if any, are safe and stable to do this to.)
- Are there any specific reasons it is not recommended to use these start options?
- Is there any actual Microsoft documentation of the purpose/uses of these start options? (I haven't found any so far.)