I'm still reading through the various links: I see that, unlike XP, Win7 search will not find anything in unindexed folders.
For now (and probably for the future too) I use a programme called 'search My Files' which is fast, customisable and thorough (and free). I've pinned a shortcut to it on my taskbar so I probably have no need to use Win7 search at all (but I will read all the links people have posted here, out of interest). Yes, possible that once I get used to the Win7 Search function, I will use it again, but I agree with James that it is not intuitive at all for someone fairly new to Win7 - and to be honest I consider myself anything but a PC software beginner: I am involved in programming and there is very little now 'under the hood' of WinXP that I am not able to fix or modify.
Thanks again for the input,
Martin