You�ll need to install itunes again and you can download it from apple�s website so you won�t need the disk.
To move your tunes over to new PC there are a number of options. You could:
-Use an external hard drive (easy)
-Use a USB pen drive (easy but time consuming if you�ve got loads of tunes
-Burn them all to CD or DVD and copy them to your new PC (time consuming but at least you get a backup copy)
-Install your old hard drive in your new PC (trickier but you get more storage on you new PC)
There are other ways but any of these will do. There are also 2 files in your Itunes folder called �itunes database� and �itunes music database� which you should also copy over so that itunes can find all your tunes. You can just let it find them automatically, but you�ll lose playlists and ratings if you do. If you decide to use these 2 files, you must make sure the music is saved in the same folder as it was on your old PC.