We are currently still running WSS 2003 SP2 at work and have not yet migrated. I have had a backup system in place for quite a while now and it was time for me to test the restoring of the backup to another box to make sure I can do it.
I had a test box called CCROWE-TEST that I was going to use to restore my data from the live system which was called NZC-AP-WSS-02
This server was running Windows 2003 Server Standard Edition with SP2 .
I downloaded the Windows SharePoint Services 2003 With SP2 Install from Microsoft.
http://www.microsoft.com/downloads/details.aspx?familyid=B922B28D-806A-427B-A4C5-AB0F1AA0F7F9&displaylang=en
I then planned to install this on the CCROWE-TEST server and then perform a backup of our live server using STSADM.EXE and restore it to the new install.
Sounds pretty simple really and in general I thought it would be.
I dbl click on the stsv2.exe which is the setup file for WSS 2003 SP2, which installs a SQL Server instance with the name of SHAREPOINT and installs the product.
After a few minutes the product is installed and now it is time to make sure my two versions of WSS are the same.
Going into Control Panel and selecting the Microsoft Windows Sharepoint Services 2.0 item I click on the support info link and get shown the following dialog.

I then do this on the live server and they both are the same - both returning 11.0.7960.0
On the new test server I go into the Sharepoint Central Administration web site in IIS and view the version of the default web site which has been configured for me.

As you can see the version is listed as 6.0.2.6568 - exactly the same version as my live server.
In order to use STSADM.EXE you must open a cmd.exe prompt and navigate to the following folder.
C:\Program Files\Common Files\Microsoft Shared\web server extensions\60\BIN
You can the run commands from the STSADM.EXE utility.
Running the utility without any parameters shows you some examples and usage:
Examples:
stsadm.exe -o addpath -url http://server/sites -type wildcardinclusion
stsadm.exe -o adduser
-url http://server/site
-userlogin DOMAIN\name
-useremail someone@example.com
-role reader
-username "Your Name"
-siteadmin
stsadm.exe -o backup -url http://server/site -filename backup.dat -overwrite
stsadm.exe -o createadminvs
-admapcreatenew
-admapidname StsAdminVs
-admapidtype configurableid
-admaplogin DOMAIN\user
-admapidpwd Password
stsadm.exe -o createsite -url http://server/site
-ownerlogin DOMAIN\name
-owneremail someone@example.com
stsadm.exe -o createweb -url http://server/site/web
stsadm.exe -o deletesite -url http://server/site
stsadm.exe -o deleteweb -url http://server/site/web
stsadm.exe -o enumsites -url http://server
stsadm.exe -o enumsubwebs -url http://server/site/web
stsadm.exe -o enumusers -url http://server/site/web
stsadm.exe -o extendvs -url http://server:80
-ownerlogin DOMAIN\name
-owneremail someone@example.com
stsadm.exe -o renameweb -url http://server/site/web1 -newname web2
stsadm.exe -o restore -url http://server/site -filename backup.dat
stsadm.exe -o setconfigdb -databaseserver server
stsadm.exe -o unextendvs -url http://server
I backed up my live server using a command like this
STSADM.EXE -o backup -url http://localhost -filename c:\backup.dat
This created me a file that I then copied to the new server.
When you restore you basically just change the operation from backup to restore.
STSADM.EXE -o restore -url http://localhost -filename c:\backup.dat
But Wait.....
You can not restore a backup over an existing site so I delete the existing site that was created by the installation using this command.
STSADM.EXE -o deletesite -url http://localhost
now I can restore my site so I use the restore command like this
STSADM.EXE -o restore -url http://localhost -filename c:\backup.dat
I receive a message that says:
Your backup is from a different version of Windows SharePoint Services and cannot be restored to a server running the current version.
OK so what have I done wrong, the versions are the same as I identified them?
Well it turns out that there was a patch for SharePoint in January that was for Daily Light Savings and also other things that I did not have installed.

Unfortunately this patch does not get added to the Add/Remove programs area, and it also does not update the version of the product that is installed!

I know most people will be now running WSS 2007, but this may help someone from wasting hours of time and frustration!
Note: I never did find a way to determine the version of the backup or the product!