Personal,xls, Personal.xlsm, Personal.xlsb . . . Use Which in Win 7??

The Windows 7 explanations shown in the Microsoft button display are:
XLS . . . . . .an Excel workbook
XLSM. . . . .XML-based and macro enabled file format
XLSB . . . . binary file format optimized for fast loading and saving
It would seem that maybe XLSB might be the preferred file name extension. But can it use macros?
]Apparently XLSM is not prevented by security from using macros, but will take longer to load and save than XLSB will.

XLS is probably prevented from using macros unless you go in and change the security settings to allow the use of macros, but is otherwise just like XLSM.

So which name extension is preferable as a general choice? I’m guessing that fast loading and saving is not an important factor for most applications, so IF your application is using macros or is likely to use them in the future, XLSM is the best choice. I’m also guessing that, if you are not using macros, XLSM will use more memory than XLS, but otherwise won’t cause any malfunctions in your workbook.

What I don’t understand is how my PERSONAL.XLS seems to get loaded for some workbooks and apparently works just fine, even though it is loaded with macros.
Are my explanations above correct, or am I wrong about something?

XL2007 has 'Trusted Locations"

Office Button, Excel Options, Trust Center, Trust Center Settings. Trusted Locations

Anything in one of the folders will open w/o Macro Security Alerts

FWIW, I always use XLSM. I re-saved my Personal.xls as an .Xlsm and it works fine

Paul

XLSB is binary, and thus smaller, and loads aster.But, it cannot be cracked open like a zip file, which might be important to you. I stick to XLSM myself, or XLS if using with 2003 as well.

I was doing some MS Help reading yesterday on XLSTART and they mentioned that Personal should be .XLS or .XLSB (now I can't remember), but it wasn't .XLSM, which I thought was odd. One of the prime uses for Personal is to store macros.

That brings up this question about .XLSM:
Just what is the purpose of using .XLSM? I assumed that it tells the world that this workbook (1) stores macros and (2) that the security setting is such that it's OK to use macros with this workbook. Neither 1 or 2 makes sense since after the workbook is stored as .XLSM there's nothing to prevent me from erasing all macros and changing the security level to "Can't use macros". I think I'll do some more reading about the file name extensions. Clearly I don't understand their effects.

There's a very good (but incomplete) KB article about XLSTART in Excel 2007 at:
Support.Microsoft.com/kb/822107
Everyone should read it!

I asume you meant below grom Support.Microsoft.com/kb/822107--

Quote:

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For example, the personal macro workbook Personal.xls is a global macro workbook that Excel typically loads from the XLStart folder in a hidden state.

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You can use a hidden personal.xls in 2003 format and have macros available, but I just use a 2007 Personal.XLSM

Paul