Where is the serial number on Olympus WS311M - Olympus WS-311M Digital Voice Recorder

The serial number is on the base of the camera. We can't give you a new serial number! They are unique to the camera.

It can be found and downloaded from the Olympus website.Here is the link for you:
http://www.olympusamerica.com/cpg_section/cpg_archived_product_details.asp?id=1308&fl=8

To learn about the new and free version of Olympus Master 2 software go to: For Windows: http://downloads.olympus-europa.com/OM2/win/OM211Setup.exe For MAC: Olympus Master 2.11: http://downloads.olympus-europa.com/OM2/Mac/OM211EN.dmg This software replaces all previous versions of Camedia Master 4.x and Olympus Master 1.x. As this is a free download there is no serial number required for installation.

To learn about the new and free version of Olympus Master 2 software go to:
For Windows:
http://downloads.olympus-europa.com/OM2/win/OM211Setup.exe
For MAC:
Olympus Master 2.11: http://downloads.olympus-europa.com/OM2/Mac/OM211EN.dmg
This software replaces all previous versions of Camedia Master 4.x and Olympus Master 1.x.

This is a free download so there is no serial number required to load the software to the computer.

Olympus Master 2 software download snippet
To learn about the new and free version of Olympus Master 2 software go to:
For Windows:
http://downloads.olympus-europa.com/OM2/win/OM211Setup.exe
For MAC:
Olympus Master 2.11: http://downloads.olympus-europa.com/OM2/Mac/OM211EN.dmg
This software replaces all previous versions of Camedia Master 4.x and Olympus Master 1.x.

This is a free download therefore no serial key is needed.

To learn about the new and free version of Olympus Master 2 software go to:
For Windows:
http://downloads.olympus-europa.com/OM2/win/OM211Setup.exe
For MAC:
Olympus Master 2.11: http://downloads.olympus-europa.com/OM2/Mac/OM211EN.dmg
This software replaces all previous versions of Camedia Master 4.x and Olympus Master 1.x.

To learn about the new and free version of Olympus Master 2 software go to:
For Windows:
http://downloads.olympus-europa.com/OM2/win/OM211Setup.exe
For MAC:
Olympus Master 2.11: http://downloads.olympus-europa.com/OM2/Mac/OM211EN.dmg
This software replaces all previous versions of Camedia Master 4.x and Olympus Master 1.x. Does not require a serial key as it is a free download.

it is compatible with vista 64bit

I don't think the serial number is required to install the software. I didn't see DS-30 information on the Olympus website. DS-40 was the closest one. No information was availbable regarding serial numbers.

I have a VN-4100PC and don't recall being asked for a serial number. The software is the same thing for all Olympus players.

To learn about the new and free version of Olympus Master 2 software go to: http://www.olympusamerica.com/cpg_section/oima_softwareMaster.asp Click on 'Free Download' to register your email address to receive an email containing a link to download either the Windows or Mac version. This software replaces all previous versions of Camedia Master 4.x and Olympus Master 1.x and is XP and Vista compatible.