The troubles occur in a PE ISO booted in VirtualBox.
A test showed that they also occur with a real burned ISO and with an USB stick. Therefore I made further tests only in VirtualBox.
Issue #1: RunOnceEx is not executed. When the PE is up, the registry key ...\RunOnceEx\??? still have content.
A manual start in the cmd window with
rundll32 iernonce.dll,RunOnceExProcessprocesses the commands and empties the registry keys.
Issue #2: I execute the self written app "easyDriveLetter" which renames the (arbitrary, depending on existing HW) drive letter of the USB or CD to a given drive letter. In PE1 it works fine, but in PE3 there are some elements:
"My Computer" shows the drive icon with the old letter and an additional blue question mark. A click on the symbol gives the error message that the drive does not exist.
The new drive letter is not shown in "My Computer":
In a cmd window:
dir "old drive letter" > does not exist.
dir "new drive letter" > shows the real content.
explorer > shows the drive icon with the old letter and the question mark.
explorer bla (wrong syntax) > shows drive icon with the new letter, and it can be opened and browsed.
Shortcuts referring the new drive letter, work well.
Question to members which are more familar with win7 than me: What to do?