XP or 7 and 32 or 64 bit?

[Kuroi-Tsubasa]

And Win7Pro and above have XP Mode, which is a VM of XP within Win7 basically. So if your app doesn't work in Win7, it'll use "XP" instead.

[invisible]

core 2 doa P9500 (6mb)

Core 2 doa, lol. I would honestly say go with XP as it has better compatibility with older software, as well as runs on slightly less resources (emphasis slight, compared to a super tweaked Seven install). A basic install is a whole 1.5GB of HDD space compared to atleast 10GB with Seven, if that means anything to you.

[atbnet]

Windows 7 all the way. There is no reason to pick anything else at this point.

[Kuroi-Tsubasa]

Windows 7 all the way. There is no reason to pick anything else at this point.

True, I'm not very inspired by Windows 8, especially the Metro interface. Sure, looks nice for a tablet, but I'd rather have the traditional Windows look and feel on a laptop/desktop.

[yukinok25]

I would recommend windows 7 too, still think he is the best and smooth OS microsoft has ever made (hope that win 8 will beat it )

I JUST formatted a laptop with a very similar specs as your,and I went straight for win 7 64bit.

Flawless

[alireza4]

I would recommend windows 7 too, still think he is the best and smooth OS microsoft has ever made (hope that win 8 will beat it )

I JUST formatted a laptop with a very similar specs as your,and I went straight for win 7 64bit.

Flawless

Can you tell me about a good reinstall OS guide for thinkpad t400. I can see several guides in this forum, but I do'nt know which is the best.

[Hungry Man]

7 64bit. No question.

[yukinok25]

I normally don't use any guide, no matter the laptop brand, the procedure is always the same for me.

But if the guides in this forum are not enough clear for you, you can try this one, seems ok to me:

Windows 7 Clean Installation - ThinkPad

[Calvin]

I would recommend Windows 7 64bit, both work fine and are forward thinking decisions. I use Windows 7 64bit on my notebook and I'm happy.

[DetlevCM]

XP 64Bit is a test OS - not a production OS.

On that note though, why use something that's dead? XP has zero protection (UAC on Vista & Win7), died more than 3 years ago and was kept alive by lazy IT departments in companies.

-> Use Vista or Windows 7 - also makes finding drivers a lot easier, Win 7 is possibly better than Vista in that too. I'm very annoyed with Intel because those lazy capitalists have released drivers for the X3100 for Win7 after they stopped developing them for Vista... and then people blame Microsoft for such companies... (or for OEMs selling an OS on underspecced machines)