Avoid Vista completely. There are far too many problems with it, not just related to ARC.

XP you will be without voice recognition unless you successfully apply the fix which is detailed on Microsoft's knowledge base, it's not something I've attempted nor want to attempt.

You can pick up Windows 7 PCs for pretty cheap now, also Windows 8 is a very inexpensive upgrade since it's sales are very low so many retailers will have deals on it, including Microsoft themselves.

Without a budget it's impossible to provide you with a decent answer on the best system to use.

I picked up a nice Acer mini notebook with Windows 7 at my pawn shop for $100.00. Now I don't need my ITX.

@usmcmp hello , I hear your on an budget but like rich pointed out that can be 50 bucks or 200 . Something I found cheap is to get a descend used computer like a p4 3ghz and maybe 2gb ram and you should be fine running win 7 if you turn off the visual bells and whistles. I recycled three dell 4000 series desktops like this to use only for ARC. If you want a tiny easier but still cheap buy a atom powered win 7 netbook or desktop motherboard both are under 100 dollars. Xp service pack 3 is what I use at work but if you want voice recognition like rich said you need win 7. You can obtain "backup copies" or restore copies usually. Just tell us what you really want and what you have to spend. - Josh S

I'm just going to throw one out there which I have read on here is a good PC for ARC and that is the Acer One netbook. £200 over here but I'm pretty sure that converts to $200 over there new, between 100 & 150 for a used one.

Yup Acer one is my favorite, they are good netbooks and you can buy them in xp or win 7.

seriously? you don't get voice recognition when using XP? that sucks. I love XP. Great, just what one needs, going out and having to buy another computer, and I was just about to go and buy my first EZ kit... oh well.

There is a fix for XP voice recognition. I've not tried it personally but it's in the Microsoft Knowledgebase which means it must be pretty reliable. Microsoft KB306537

I do on my computer(Windows Xp SP3). Search your control panel and if you see a "speech" option, you have it. But you may need to find a microphone or headset to use it.

It is not part of Windows XP SP3 (see screenshot below), it is an extra that requires downloading. It is also part of some other Miccrosoft software such as Office 2007. Unfortunately Microsoft has discontinued one of the old pages for Speech Recognition and the other has been taken over by "Tell Me".

The knowledgebase article should be enough to get it installed though.