What does gpupdate actually DO?

I cannot find an explanation of what gpupdate does, beyond something like "updates the group policy." But I can't find any definition of what that means. I'm looking for a more detailed explanation. For example, something like:

"It transfers group policy settings from the files in c:\Windows\System32\GroupPolicy into the current registry control set."

or

"It takes the current registry settings that are related to group policies and makes those effective in the running system." (Is there even a concept of a CurrentControlSet registry setting not having immediate effect?)

or

"It takes the registry settings that are related to group policies and back-dates the c:\Windows\System32\GroupPolicy files to reflect the current registry settings." (Yeah, I know it's probably not this.)

or

"It does both of the first two items."

or

...? (something else?)

Any clarification is appreciated. Thanks in advance.

My understanding is that it forces a re-read of the registry's 'policy' keys, nothing more.

Hope this helps...

You mean something akin to my second "or", RickC?

So you might do a "REG ADD ..." and then you'd do a gpupdate to make that take effect right away?

Say for example you change a group policy in gpedit.msc to turn off autorun. But you want that to invoke now, not latter, not with a computer restart, but now. So you run the command gpupdate and it's invoked right there and then.

Now you know.

dpengel3 said:

You mean something akin to my second "or", RickC?

So you might do a "REG ADD ..." and then you'd do a gpupdate to make that take effect right away?

Yes. The registry itself is not a 'change' mechanism per se, merely a repository of settings... even though, admittedly, some changes are dynamic. That's down to the OS, not the registry.

Gpudate instructs the OS to re-read and act upon the 'policy' keys.