i have got this hard drive to boot on computer 1 but when i go to boot it on computer 2 it doesnt boot fresh install of windows hasnt been activated yet just shows up a black screen i can get into the screen to select safe mode with f8 but this doesnt work i've also tried the fixboot and fixmbr commands with recovery console i just installed this copy of windows on the hard drive and got it to boot on computer 1 with no problems dont know what could be wrong

You can't just install on one machine then move to another. Re-examine why you think you can do that. Doing so will answer your question. Knowing the correct answer and giving a correct answer, are two different things

Xp saw a huge hardware change from PC1 to PC2. Microsoft does wan't you installing Xp on multiple PC's without buying additional license. That's probably why it won't boot from the hard drive for you on PC2.

Sometimes you can get it to work by running a system repair from the recovery console or the xp cd.