Thanks for the replies guys,
Orbital Shark- I just checked everything in my BIOS. There is nothing relating to OS in anywhere not even advanced options.
jfar.- I don't get a boot choice at all. The system starts and I get the Asus page then I get a blinking cursor and, after a few seconds, the disk read error message.
By booting from my Vista disk and then clicking repair I get a box with the following in:
Windows 7 112172MB (e

New volume
Microsoft Windows Vista 364764MB (d

Local disk
Microsoft Windows Vista 364764MB (d

Local disk
Windows 7 112172MB (e

New volume
I have tried the repair option with both disks (vista and Windows 7) and it tells me there is nothing wrong.
Wish I'd left it alone but I wanted to have more room for Windows 7 so I could install more programmes and use it as my main OS.
I'm completely lost, John
Just noticed these smilies. They are supposed to be colons. Must be some foible of this Asus expressgate emergancy os