Did you try contacting Larian (
DKS support) and/or Stardock? Someone mentioned yesterday there was a problem with the FoV patch (updater not recognizing FoV was installed) that an update from Stardock resolved.
In question 2.3 of the FAQ I linked to above, the locations of the Securom data are listed for different Windows versions. Registry entries can be changed or deleted with a registry editor (not sure about Windows Vista/7, but it was regedit.exe in earlier versions). Securom may have a tool to remove its drivers and data, which would probably be easier and safer than doing it manually if you are not familiar with the procedure.
To browse to the appropriate folder in Windows Explorer, you may need to set it to show hidden files and folders (
XP, Vista,
Win 7).
Also, question 2.10 in the FAQ requests a picture of the serial number if you get a error that it wasn't found, and it wasn't a case of replacing a 0 with O or 1 with I, etc. Windows 7's Paint can probably crop a screenshot and save it as a png file (or gif, or a bmp file might not be too large), otherwise there are many freeware graphics editors or viewers than can make simple edits (such as
IrfanView).