iPod Touch/iTunes help/advice needed.

[Junkmale]

Does anyone know anything about how iTunes works?
To cut a very long story short i've been having some PC problems lately.
I ended up needing a new Hard Disc and i've lost everything from my old one.
iTunes is now recognising my new h/d as a new computer?
When i connect my ipod touch all my existing apps are showing ok.
However last night i bought a few new apps and itunes is telling me that i can't sync the new apps without removing all of the apps i had already installed back before i changed the h/d?
Does that make any sense?
Any help/advice would be greatly appreciated.

[Junkmale]

All sorted now.
Mods feel free to delete or lock.