IE 7 Visitors and to how identify them

in the raw web logs

[Tidal2]

My file stats software informed me I had my first IE 7 visitors in September.

When I search the raw web logs though I can find no sign of them, can anyone tell me how they are identified?

[dcrombie]

Here's one:

Mozilla/4.0 (compatible; MSIE 7.0b; Windows NT 5.1)

;)

[Tidal2]

That's the one, thanks very much.