I am thinking of upgrading from XP 32bit to Windows 7 32bit Home Premium FP for 3 computers.
Biostar TA770E (AM2+)
AMD AthlonII 240 X2 (2.8GHz) AM3
OCZ 2GB 800MHz DDR2 (5-6-6-18 Dual-channel)
Palit GeForce GTS450 1GB
Microsoft Windows XP 32bit
WD Caviar Blue 160GB SATA2 3.5" 7200rpm
CiT 1008 Piano-black Midi-ATX
CiT 500w (Dual-rail +12V combined amperage of 27)
I use computers only to game, download and browse the internet. I play alot of old games as far back as 1998 but also play the newest like Bad Company 2. I see that I can buy it for £96 ($150) from Microsoft site as an upgrade but is it a worthy and future-proof investment?
I think Win7 is a great OS but I can't see any compelling reason for you to make the jump over to Win7.
As you replace your older systems you'll get Win7 already embedded in the cost.
That £96 is very nearly 25% of the cost of a new general purpose PC or laptop.