Thanks for helping!
The computer is only running windows 98 with bare minimum settings, Mame and Arcadeos - nothing else. Apart from Arcadeos the startup menu is empty. I have just tried another front end (Gamelauncher) and had a similar result making me think I have a conflict somewhere, but just not sure where.
When Arcadeos or gamelauncher is run from the desktop, all is just fine, works and sounds a treat. However, if either are dragged into the start up menu the machine will boot up, show a window indicating that the program has been loaded and then simply flick back to the windows page with the program shown as a minimised box on the bottom left toolbar. Any attempt to click on this box simply freezes the computer. With gamelauncher, I had a similar experience, but did once see a square message box appear on the monitor briefly that said Signal out of range
FH23.7
FV37.7
I don`t know what these mean, but I am using standard on board sound and graphics, both of which work very well when used after windows has loaded fully, hence my initial thoughts of slowing down the loading of the program to allow something else to load first, but this obviously isn`t the case.
Any further thoughts greatly appreciated