Vaio VGN-FW21Z DVD-Rom missing driver on windows 7

Hi everyone,
I have a Sony Vaio VGN-FW21Z Laptop, i bought it with Windows Vista installed on it but i changed the windows to Windows 7 and now the dvd-rom doesn't work anymore.
I have read on internet that the problem can be from the drivers. I can't find any driver for windows 7 for my dvd-rom.

Try this (1):
Your CD drive or DVD drive is missing or is not recognized by Windows or other programs
Fix problems with CD or DVD drives that can
The CD drive or the DVD drive does not work as expected on a computer that you upgraded to Windows Vista

Try this(2):
1) Shut down PC.
2) Physically disconnect the CD/DVD Drive.
3) Reboot to Windows with NO DVD drive.
4) Shut down PC.
5) Physically reconnect the CD/DVD Drive.
6) Reboot to Windows with DVD drive.
7) Check Device status.

I've tried the first tip you poted... don't work.
My DVD-Rom is a MATSHITA BD-MLT UJ230AS.
I hope it is usefull