New build - can I use my old version of XP?

I need to do a new build so I have a system powerful enough for video editing.

I was thinking of using the XP home that is on my current PC on the new PC. Will Microsoft allow that? I have not tried since the old days of unlimited use Windows 98, so I am not sure if you can transfer XP from one system to another.

Thanks for looking.

Thanks for the reply Grumpy. It is Retail. Do I need to get Microsoft involved or can I just load it to the new pc and go?

You should be able to put XP on your new system,
you will not need to contact Microsoft, all you need is the licence key when you put it on your new system to activate windows XP on your new system,
this licence key came with the retail copy of XP when you purchased it,

BUT ! remember that this key may only work on one pc at a time, so you cant have 2 PCs in your home using the same key, unless this version you have was a multi user key that can be put on something like 3 PCs at a time.