thankyou Charles <<The Serial Number? Yes. You can set it in winecfg. >> ah yes the Advanced button <<There's a similar file for the serial number, called .windows-serial>> I forget the hyphen in my blind experimenting :-) <<Either it's designed for Windows 9x, or your Windows version is set to Windows 95/98/ME>> Yup I had it set to Win98 for other reasons setting it to WinXP get Error reading drive: Bad device type many thanks, I was not particularly looking to make Volumeid work, it was just an attempt to set the Volume Serial Number having determined that it was not set at drive creation. Only remaining question / suggestion is that a (random) Volume Serial Number should be created during wineprefix creation to mimic real.