The location of that folder depends on the version of windows and the version of
excel (and even your upgrade path).
I like this way to find the XLStart that excel likes:
Open excel
hit alt-f11 (to get to the VBE where macros live)
hit ctrl-g (to see the immediate window)
type this and hit enter
Print application.StartupPath
For me (xl2003 and winxp), I get:
C:\Documents and Settings\(username here)
\Application Data\Microsoft\Excel\XLSTART
(all one path)
==
Some people record macros directly into their personal.xls file for common
routines. I've always recorded into a test workbook, then tweaked the recorded
code. After I was happy with it, I'd just highlight the code and copy|paste to
a module in my personal.xl* workbook project.
If you're going to be experimenting, remember to back up your personal.xl* file
often. If you screw up, you'll be able to copy the older version back to the
XLStart folder.
(It's very easy to screw up when you're doing stuff.)