It seemed confusing to me when I read the "About>FAQ>What will I need to play?" that it said you could either have Half Life 1 and/or Counter Strike (original retail) to install the game. But then I still can not install the game properly even though I have Counter Strike and keep getting the "Setup has not detected a valid Steam install". So is it just HL1 that will run NS or am I reading an old FAQS that hasn't been updated yet?

Old FAQ afaik.

It used to be that you COULD run NS from CS Retail, however it looks like you can't any more (there is a guide on how to do it floating around, but no one seems to be able to get it working any more).

honestly, buy HL (and PLAY IT!)

Meh, Thansal (as always) does not provide trustworthy information:

In the WON days you could run NS from a CS retail installation.

Nowadays you can still run NS with only owning an old CS retail, because registering that CD-key with steam will grant you access to the whole steam back-catalogue, which includes half-life.

You could also get NS to work with a CS:CZ steam installation and without half-life. But I am no sure if that applies anymore.

Thanks, but that sucks all around... I have almost all the valve games cept HL1. Well i guess i am gona have to get some money *sighs*.

I thought you could run NS in Steam with CS:CZ OR CS? (and that it now does not work)

either way, go buy HL. (AND PLAY IT!)

Iirc there was a point in time, where a steam cs install could not run ns, but a steam install cs:cz could, cause it shared some required gfcs with half-life.

I have the same problem, cant get it to work, I got the Counter-Strike Anthology but it keep saying "Setup has not detected a valid Steam install" even if i uninstalled steam and reinstalled it again...
It worked for my friend and he got the anthology too, So wouldnt it work?