1. I agree with the others, you probably won't be able to run it on any computer. The hardware is simply not compatible with the software.
2. I think the changes from EQ3 to EQ7 are radical enough that if you tried out EQ3, liked it, and bought EQ7, it would seem like a totally different program.
3. As an aside..... as you probably know, Microsoft stopped supporting XP. This means there are no anti-virus patches, bug fixes, or updates for it anymore, so be very careful about what you download, open, install, etc.
I put out the word amongst my quilty friends and local quilt shops that I was looking for a used copy of EQ7 for my mom. I found someone willing to sell me hers for a
very reasonable price. Check around your area, maybe you'll find a deal too!