Jim, I've done great using XP as my virtual Machine for years!  It's time to grow up and do a new  Windows 10 virtual machine  or should I just upgrade the XP machine.   If I build a new machine should I use the size that I currently have for XP or does 10 take a lot more space? I share files but I do not mirror desk tops as I use Mac and Windows independently, however all of my designs, and other data saved to the Mac not to Windows.  Why am I doing this...Microsoft is giving me 30 more days to use XP because I can't find the Key Code even though  I can find the validation code, have the installation CD and have my original receipt!

Microsoft's efforts to stop piracy have had almost no effect on pirates, but it causes myriad problems for legitimate users like you. XP is at end of life, so this is a good time to upgrade. However you will have to buy Windows again, unless you already have Windows 10. Personally I like Windows 7 better when I have to use Windows. There are a lot of software "surprises" with 10, although it is getting better. I would set the hard drive at 60GB, which should be enough. Don't preallocate it. That way it will grow as needed, and you won't use any more space than you absolutely have to. Windows 10 will run on 4GB of RAM, but give it more if you possibly can. If your MacBook Pro has 8GB, give Windows 5 or 6. This won't impact the Mac that much, as it will only be in effect when you're working in Windows.