Mac OS X Folder opens up whenever Macbook turns on

I'm not sure I understand what folder you mean exactly? Are you referring to a reguar Finder window? Can you post a screenshot of the folder please.

FWIW, the OS automatically will open any window that was open when you shut down your machine - so do you have any open windows when you shut down?

Any Finder window left open upon shutdown will reopen when you restart. This has nothing to do with the new Resume feature. This was always and still is the case even in Snow Leopard (can't remember about previous iterations).

Only way to prevent it is to close all Finder windows before you shutdown.

If you're doing that and its opening a window that wasn't open when you shutdown, try deleting the plist file:

~/Library/Preferences/com.apple.finder.plist

(to get to it use Finder > Go > Go to Folder... and type or paste ~/Library/Preferences in the dialogue box)

Then restart.

Hi. I am having this exact problem (except that it wasn't initially a problem with my new MacBook with Lion, but rather started happening one day and I don't know what I might have done to prompt it).

I perused System Preferences for awhile but couldn't find the option to hide everything on Login. Can you share where in System Preferences you found that option?

Thanks so much in advance!

liz

Thanks much for the clarification.

Unfortunately that didn't resolve it for me. Tried it and still, every time I restart--closing all apps and de-selecting the annoying default to re-open any open windows upon restart, just in case--it still always (slowly) opens that Mac OS X window in finder every time I start up the computer. Gah.

Any other suggestions out there?

See my edited reply above. ^

Can you please post a screenshot of that window - it sounds as though it is an installer window. What have you downloaded/installed lately?

Just out of curiosity, what did you have in Login items that is now disabled/no longer a problem?

Ahh, Symantec - so you have Norton's installed? Why? Are you running Windows? If not, I'd get rid of it. You can read some relevant information here:

http://www.reedcorner.net/guides/macvirus/