I figured this was as good a place as any to ask.
There's an old game, the name of which escapes me, can you lot help me?
It was a fully 3D RTS, first or third person (variable). In this game you built a base and units controlled by AI and commanded them. You could enter into any of these vehicles, however, and control them. It lacked a dedicated isometric view, but in the command center you could view the battlefield in the traditional way, but for the most part you were at the heart of the action. In alot of ways it was similar to Command & Conquer: Renegade (but predated it). There was a sequel as well.
Any help would be appreciated, my memories of it are kind of hazy, but I've got the premise down pat.

Battlezone? I think Battlezone was pretty similar.
EDIT: Zombus, you're one fast typer! I Giant Bomb'd Renegade, looked at similar games, and found Battlezone.

Haha! Brilliant!
Thank you so much you two. It was Battlezone 2 I was thinking of.
Very, very much appreciated.

You can get Battlezone and Battlezone II to work in XP/Vista, though there is some fiddling involved, at least with the first one. I think that the second one works with relatively few problems, if you update it. I was thinking of installing BZII anyway, so I can test it here (Vista 32bit).
EDIT
Battlezone II works fine in Vista 32 bit, using the v1.3 Public beta 3 unofficial patch it seems. Forum reports seem OK, and I managed to start up a game, and play around for a bit without any problems.

If its for win98, you could probably just copy the files off the disc over a network and install that way, maybe even share a CD drive over the network or use an ISO image of your disc and a virtual drive?

Battlezone 2 works just fine in XP. Not sure about Battlezone 1 on XP or either of them on Vista.
However! Battlezone is not the game I was thinking of afterall! I thought it was until I started playing it, so the search continues. The game I'm thinking of had graphics on par with Descent 2, roughly - I know it predates Battlezone 2 and it isn't Battlezone 1. It's title was also a compound word. For the life of me I can't remember the name though it's so close to the tip of my tongue I can taste it!
I hope someone here can help me - I'm dying to play that game again.

I can announce the search is over.
After an exhaustive search fueled by caffeine and obsession, I found my own answer after almost 12 hours of digging.
The game was called Uprising. It came out in 1997 and did, in fact, spawn a sequel. It did everything better than Battlezone, and was arguably a better game than CnC: Renegade all around. Thanks for those of you who helped! If anybody needs any info themselves, I'll be around. For now, this is going on my wishlist!