I have the same problem, with the "Fn" key on a vaio notebook VGN FS600w becouse i had to format my lap to reinstall antoher OS., before i do that, I made the recovery cd's with the recovery wizard software and all its well, except the "Fn" key.
So i contact the technical suport and they told this:
"Your notebook requires a program called HKSERV.EXE in order for the function (Fn) keys to work properly. Follow these steps to enable HKSERV.EXE to run when Windows starts:
1. Click Start and then click Run.
2. Type "MSConfig" in the open box (Without Quotes) and click OK.
TIP: Windows 95 does not offer the MSConfig utility. To re-enable
HKserv.exe, please reinstall the HotKey application from your
Application Recovery CDs
3. Click the Startup tab.
4. Click HKserv.exe to place a check next to it then click OK.
5. Restart the computer when prompted.
TIP: If you do not find HKserv.exe listed, you must reinstall the
HotKey application using your Application Recovery CDs or
TIP: Under some rare circumstances, it may be necessary to also create
and include an HKserv.exe shortcut -
C:\Program Files\Sony\Hotkey Utility\Hkserv.exe
in the Windows Startup folder. This will only be necessary if a
third-party software application has been installed that prevents
the HKserve.exe application from executing properly."
That didn't help a lot couse i did not find the hkserv.exe.
Otherwise, i find something in this forum that maybe could solve our trouble.
the link (ftp://ftp.vaio-link.com/PUB/Vaio/Hotkey/
) shows you some aplications for reinstall this utility, i have no tried already, but i'm in the way, so i expect that solve our problems