help-what does this mean?

[cheesesarnie]

'the disc containing your index is almost full.' keeps coming up on screen i keep clicking ok but just goes and comes back after few minutes.

I don't recognise the message, but IS your drive nearly full? Have a look in My Computer. Right click C: and click properties (or change view to Details mode)

Properties will also show you if Indexing is ticked. If so and you're running out of space it might be that function which is doing the complaining.

Indexing makes some kind of huge list to speed up searches so it must take up space.

If it is nearly full then empty the recycle bin then go to Control Panel. Double click 'Internet options' and on the 'temporary internet files' bit click 'delete files'
Then check how much space free.