Installshield wizard not enough disk space error

Ok so i get all excited about a brand new game... I pop it into my DVD drive on my overclocked 4ghz computer with a brand new terabyte hard drive. I click next, choose my directory program files/game then i get the error---

There is not enough space to install these option(s).
Please free up disk space or modify your selections. ----

Ive been getting this problem for all the games that use this install shield such as Ghost Recon Advanced warfighter, Neverwinter Nights 2 etc... I have nearly 900 gigs of free space and ive tried changing the install directories. Ive also tried creating virtual partitions but with the same error. Ive tired creating ISO's from the DVD's and still have the same problem. Is there some bug out there that disagrees with large hard drives or something?

specs are 8500 Duo 3.1ghz (tried overclocked and regular), 1 terabyte HD, 4gig ram, P5E Deluxe ASUS motherboard, ATI radeon 4870. Im all out of ideas. Does anyone else have one?

I swear Im about to forever leave windows and switch to linux. there is no point in having windows if i cant even play the games i want.