Please explain how file/program associations work.

[Dennis Marks]

I know that there are default file/program associations for many file
extensions. When you change the association to make a file use another
program where is that stored? I changed an XLS file to use OpenOffice.
It is not listed in tools/folder options/file types. Where is it stored?
If you change it for only one file is it stored in the file itself? The
file still shows that it is an "Excel Worksheet" but opens with
OpenOffice. How does it know that?

I did an experiment and changed the XLS extension to qws and it shows
that it is a "qws file". When I change it back to XLS is shows
"Microsoft Excel Worksheet" opens with "Open Office". Where is that
information stored on the computer?

--
Dennis M. Marks

Disclaimer: The above is my opinion. I do not guarantee it. Be sure to
back up any files involved and use at your own risk. Batteries not
included. Not for internal use. Don't run with knives.

 

[Wesley Vogel]

In the registry. These are from my registry and I do not have Excel
installed, I use Microsoft Works Spread (sheetwksss.exe) to open .xls files.
I used FileExtInfo to generate the following list.

[HKEY_CLASSES_ROOT\.XLS]

[HKEY_CLASSES_ROOT\.XLS\Excel.Sheet.5]

[HKEY_CLASSES_ROOT\.XLS\Excel.Sheet.5\ShellNew]
"FileName"="excel.xls"

[HKEY_CLASSES_ROOT\.XLS\ExcelWorksheet]

[HKEY_CLASSES_ROOT\.XLS\ExcelWorksheet\ShellNew]
"FileName"="excel4.xls"

[HKEY_CLASSES_ROOT\.XLS\OpenWithList]

[HKEY_CLASSES_ROOT\.XLS\OpenWithList\wksss.exe]

[HKEY_CLASSES_ROOT\.XLS\OpenWithProgIDs]

[HKEY_CLASSES_ROOT\.XLS\OpenWithProgIDs\MSWorks4Sheet]

[HKEY_CLASSES_ROOT\.XLS\PersistentHandler]
@="{98de59a0-d175-11cd-a7bd-00006b827d94}"

[HKEY_CLASSES_ROOT\SystemFileAssociations\.XLS]

[HKEY_CLASSES_ROOT\SystemFileAssociations\.XLS\shellex]

[HKEY_CLASSES_ROOT\SystemFileAssociations\.XLS\shellex\
{BB2E617C-0920-11d1-9A0B-00C04FC2D6C1}]
@="{9DBD2C50-62AD-11d0-B806-00C04FD706EC}"

<quote>
FileExtInfo utility is a small helper application that gathers information
about the association settings for a chosen file type. It exports all
possible registry locations that are associated with a particular file type.
The information (REG format) is consolidated and presented in a single text
file, to make troubleshooting easier.
<quote>

FileExtInfo - View the association settings for a file type easily
http://windowsxp.mvps.org/fileextinfo.htm

--
Hope this helps. Let us know.

Wes
MS-MVP Windows Shell/User

In