Hi there,
I do have a second drive (E:/) in this PC and it is only a quarter full so plenty of space. I keep hardly anything on C;/ enough to run the PC basically.
Ran CCleaner and managed to get things going a bit faster, but that was under guidance from a friend who knows more than I do. He is coming in to set up the Zoostorm for me and get it running properly and have a look at the Laptop. The IE screen now says Acer at the top which is the make of it. But nothing much can be done with it, cannot change a link if I go to a site. Bloody stupid MS....
So yes, I do have a second drive I can run another OS from if that's possible.
Went to the shooting range today and took out my fury and annoyance on some targets...
Haha, that's a great stress reliever.
I'm assuming you have a copy of 32-bit XP available; OEM versions such as those from Dell, HP, etc. usually won't work. First, find out the motherboard make and model using Belarc once you get your new PC, or call Zoostorm. Once you have that, you can get drivers for the appropriate model here:
http://uk.gigabyte.com/support-downloads/download-center.aspx
Download the XP ones onto a memory stick. Be sure you're downloading the XP 32 bit versions, not the XP-64 ones (unless you have XP-64. I do and love it!

) You'll need the Chipset, Audio and VGA/Video drivers. Also grab the LAN driver if you want to be able to use internet on the XP partition. Some of my partitions DON'T have the LAN driver and, thus, no internet, which greatly improves performance and eliminates the need for anti-virus software, firewalls, etc. You can still email, do internet, download, etc. from the Win7 partition when it's running. Just something to consider.
You/your friend will have to install the second disk in a spare drive bay. One that's done, dual booting with two or more hard disks is simply a matter of popping your XP CD in the drive and installing it on the second disk. Just be sure you know which is which. Windows will identify the drive by it's hardware name or manufacturer ID. I prefer to temporarily unplug any other drives while formatting with Windows, only because that eliminates any possibility of formatting the wrong drive (and I have many drives with similar or identical IDs, so it's quite possible) but not everyone does that. Just as long as you install to the right drive, you'll be fine. Once Windows is installed, run the driver installers from your USB stick. That's it.
When you go to start your computer, you hit F12 as it's starting to select which Windows partition. Your second drive will probably be called "HDD1", assuming the Zoostorm folks set up your machine properly, while the Win7 drive will be on HDD0. If you want to make the XP drive the default one the computer boots to, go into the BIOS and try to find an option called "Set Boot Priority" or "Set Boot Order". Make HDD1 the first on the list and HDD0 the second. Save and exit.
I don't know if TRS2006 would benefit from the /3Gb switch that lets would allow Trainz to use more memory than it normally would. Maybe someone else can chime in on whether that's worth enabling on XP.