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I was always under the natural assumption that the Pentium 4 was 32-bit only.

But I just got a new graphics card and went to download the 32-bit driver for Windows 8. During installation, I got an error prompt saying that the OS was not 32-bit and that installation couldn't continue. So I go to the Windows properties page and lo and behold, the 64-bit version of Windows 8 was installed. How can this 64-bit OS be running???

Later Pentium 4 models, from the Prescott core on, are 64 bit. Some individual ones had it disabled initially so Intel could reveal it later as a sales booster, but most late P4s have it enabled. Looks like your's does.

The later P4s had 64-bit instructions.

http://en.wikipedia.org/wiki/Intel_64#Intel_64

Wikipedia wrote:

Intel NetBurst microarchitecture

• Intel Xeon (all models since "Nocona")
• Intel Celeron (some models since "Prescott")
• Intel Pentium 4 (some models since "Prescott")
• Intel Pentium D
• Intel Pentium Extreme Edition

Intel's list here.

If I remember right, the second revision to the prescott (presHOT) and the following Cedar Mill were 64bit. The Cedar was the last of the pentium 4 and the "best" of the pentium 4. 65nm, better power control, more cache, etc....but still a pentium 4.

Edit: that was fast...

Gentlemen, I do believe we have solved this case in record time! Beers at the pub are on me!

man, you guys are fast! *thumbs up*

alright ran CPU-Z because it was killing me to know what was in my dad's computer...

It's a Pentium 4 630 Prescott 3GHz. 90nm. family: F. model: 4. stepping: 3. revision: N0.

learn a new thing every day... apparently, my ignorance led me to install Windows 7 32-bit way back when. the system originally had 32-bit Windows XP Home Edition.

Well, assuming you didn't have enough RAM to actually *need* a 64-bit OS, no harm done!

onlysublime wrote:

man, you guys are fast! *thumbs up*

alright ran CPU-Z because it was killing me to know what was in my dad's computer...

It's a Pentium 4 630 Prescott 3GHz. 90nm. family: F. model: 4. stepping: 3. revision: N0.

If I remember right the socket 775 Prescotts support 64bit, the socket 478 are 32bit only.

tfp wrote:

If I remember right the socket 775 Prescotts support 64bit, the socket 478 are 32bit only.

Going through the Wikipedia page for the P4, that is correct. I see that x64 chips started showing up on the P4 5xx series which was LG775 only (mostly new steppings with no clock speed increases released in 2005). The 600 series (Prescott 2M and Cedar Mill) was all x64.

Might be also worth mentioning that Intel's mobile processors didn't get x64 until Core 2.