I have some context information below, which is untopical. Please bear
with me.
I've just bought a Lenovo X230 laptop to replace my X61S .
I have Windows 7 Enterprise Service Pack 1 32-bit.
[I googled to find how to get this information; a link required
Silverlight to be installed to give me the information that I needed to
do Start/Computer/Properties. I actually needed Start/Computer/System
Properties.]
That is REALLY good for me. I have some personally important software -
mail and news handler - which does not work on 64-bit.
While I do not have W7 Media, I can add and remove Windows features - I
tried with Telnet Client.
I have Microsoft Office Professional 2010. Again, lack of media does not
seem to be a problem.

Now I get to my difficulties. In 2003, I run with low security and
happily put VBA macros in .xls files. 2010 seems willing to read such
files, but, by default, creates .xlsx files, which I can't persuade
Excel to hold macros. I have many .xls files in which I write an
auto_open macro:
Option Explicit

Public Sub auto_open()
Application.Run "PERSONAL.XLS!CheckDateConsistency"
End Sub
"PERSONAL!CheckDateConsistency" fails, 2003 does not type default.
2010 prefers to have macros in .xlsm files.
I can probably cope with the default file type being .xlsm, but the
default file type is .xlsx.

If I copy my PERSONAL.XLS to
C:\Users\Lenovo\AppData\Roaming\Microsoft\Excel\XL START
[...AppData... as a hidden directory was an issue til I changed with
ATTRIB -H]

when I run any macro in PERSONAL.XLS, loading fails, I get "Compile
error: Can't find project or library", focus is (spuriously) put on a
call of the function Left and I am shown a list of libraries including
MISSING: Microsoft Office Runtime 1.0 Type Library
and
MISSING: Microsoft Office Control 1.0 Type Library.

Unchecking both allows PERSONAL.XLS to compile without error.

I have files copied and openable. 2010 uses 7 lines above the column
titles; 2003 uses 6. A small difference, but my new 12.5" screen is
16:9, my old one is 4:3. Ctrl+F1 toggles hiding and showing the ribbon.

I would appreciate pointers to some good porting documentation.
I want to move to 2010 with minimal pain and change. ;)
(I also make some use of Word. I trust Excel lessons will easily port.)
--
Walter Briscoe