Want bigger window for Windows Virtual PC after winXp installed

A 1st time here in having installed Windows Virtual PC after which I installed Windows XP from my old original CD (yup I still kept it). Anyhow I fooled around a bit with with desktop setting and managed to get the window a little larger but it is still to small. Is there any way of getting that window larger, or even full screen?
[I installed the virtual machine and XP only so I could play old games (STEAM) on them since other methods proved unsuccessful) ].
Thanks

Thanks buddy. It was not possible to maximize the window hence y I wrote here. But, you know what you are right. The Micsft VM is causing a whole bunch of other problems. Too many headaches for me to go bananas over just due to the occasional game. I think I will try VirtualBox followed by VMware (as you suggested) since the latter seems to be a little harder to configure than the former.
And as to Steam maybe not working as I hope. I am expecting that and if such be the case than so be it.
Steam sold me a series of games which even in their own page, (more than one) they advise that it is not compatible with Win 7, and yet, even after the fact they refuse to give me a refund. I knew of their 'no refund' policy but in this case I thought there should have been an exception since it is they who sold me a game which can't be played/used-- equal to selling me a defective non-working product as far as I'm concerned but I stopped the fight after a while since we are talking about, about $10 I think--and I think the knew the fight would stop given time.

Thanks will prabably give it a try if the already installed VB doesn't suit me. Meanwhile though there is another question: It seems as if the default choice is Wndows XP 64 bit. I'm assuming that thought my PC is obviously msde for 64bit and my Current OS is 64bit should I follow the XP 64bit as well? I was thinking not since my Win XP CD is 32bit: what I have on my XP is "Windows xp Home Edition -- Version 2002"

Thanks whs. I had assumed not using an iso, but my actual original CD, that it would matter. Anyhow, thanks as well for the vmware suggestion, though I knew of it, your suggestion made me try it even more, since I was not happy with the other 2. Unfortunately, it too has its problems: its virtual VGA card isn't recognized by steam, and as u may recall, it is the main reason for me installing a virtual machine. If I can't fix this I will have to scrap the whole idea.

whs said:

There is one other suggestion I could make - although I never tried that wirh XP. Install it on a flash drive. Here is a tutorial I once made for the installation of Windows 8.....
Just make first sure your PC can boot from a USB stick. I also recommend to use a stick with a fast access time - preferably under 1ms. USB3 is of course preferable. ....

OK got myself a bigger and faster USB stick and am ready to try out what your tutorial suggests. Here's the problem I ran into. Your tutorial says both Win 7 & Win 8.
In step 2 mounting the WAIK it is not clear if your doing this, reading and mounting info related to my actual OS (Win 7) or the XP ISO, which logic would imply it is not doing so the info attained here is in reference to '7'
so when later it says to choose either 32bit or 64 bit version I am assuming it is still referring to Win 7 (or 8 I think in your example) which when going to "Step 3 - Mount the Windows 8 .iso in a virtual BD ROM" In my case it would be my XP iso but considering the previous steps may have nothing to do with my XP.
So I think somehow when earlier I run the WAIK somehow I have to direct it to my XP iso instead. Anyhow, as you can see I am running into problems. Any guidance?