I used Live Search with "Excel comment font" and found this info on Debra
Dalgleish's site

http://www.contextures.com/xlcomments02.html#Default

Change the Default Font Size
You can change the font size of new comments by changing the settings in
your Control Panel.
(Instructions for Windows XP)

1.. Right-click on the desktop, and choose Properties
2.. On the Appearance tab, click Advanced.
3.. From the Item dropdown, choose Tooltip
4.. Choose a font Size, click OK, click OK
(Note: selecting a font type here will not affect the default font used in
Excel's comments)

best wishes
--
Bernard V Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme
remove caps from email

"CThomas" wrote in message
...
Please help!
I have to send many Excel files with comments to a coworker who cannot see
well. How can I permanently change the font or font size of comments in
Excel
so they are bigger than the default of Tahoma 8? My current default font
for
Excel is Ariel 12 so I know the two are not related.

There has to be some function I am missing as I have scoured the internet
looking for an answer to no avail