new build with old hard drive

i am building a new athalon 64 system but i am using my hard drive out of my old sony 1.8 piece of crap and the cd drives and floppy drive als.i have a new copy of windows xp and need to know what i need to do after it is assembled.do i just pop in the xp cd and reinstall it or is there more i need to do.this is my first home build so i have no clue.any help would be appreciated.

just pop it in and either reinstall from a format or just do a repair install.

I would recommend a clean install, less likely to have problems with a clean install. Just format it and install Windows on it and you're set.