* On Windows Vista, [Run] section entries with the postinstall flag no longer inherit Setup's elevated privileges by default, and instead now execute with the (normally non-elevated) credentials of the user that started Setup initially. (There are some exceptions; see the runasoriginaluser flag documentation for details.)
* Added new [Run] section flags: runascurrentuser and runasoriginaluser. These control which user credentials are used on Windows Vista when spawning processes. (runasoriginaluser is the default when the postinstall flag is used; runascurrentuser is the default otherwise.)
* Improved compression of x86 executable files. (This reduced the size of Inno Setup's own installer by approximately 10 KB.)
* Added new [Files] section parameter: ExternalSize.
* Added new constant: {log}. Translates to the log file name, or an empty string if logging is not enabled.
* Added new [Files] and [Dirs] sections flags: setntfscompression and unsetntfscompression. These flags instruct Setup to enable or disable NTFS compression on the file or directory.
* Pascal Scripting:
o Added new ExecAsOriginalUser, ShellExecAsOriginalUser, and SetNTFSCompression support functions.
o Now supports new DLL loading flag loadwithalteredsearchpath to load DLLs with the Windows flag LOAD_WITH_ALTERED_SEARCH_PATH.
* The Setup loader now uses the original Setup EXE filename + .tmp as the filename for the extracted Setup executable instead of a name comprised of random letters and numbers, which may have seemed suspicious to firewall users.
* In a multilingual installation, Setup now waits until after the Select Language dialog is shown to display any error messages concerning the user's Windows version or privilege level.
* Fix: On Windows Vista, AutoPlay wasn't being suppressed when the user swapped out discs in a disk-spanned install.
* Fix: When the waituntilidle flag was used in the [UninstallRun] section, it behaved like waituntilterminated.
* Based on RemObjects Pascal Script SVN code revision 1045a.
* The uninstall program's version is now 51.48.0.0.