If you have removed the harddrive the warranty is over thats for sure.
Second 3200 + songs and yer saying you havent downloaded in 2weeks.
That suggests you have downloaded before.
So thats every reason to suspect a virus as sometimes they dont do any damage for awhile.
if you have now removed this harddrive and voided the warranty. I would suggested getting an adapter and connecting it to a desktop pc and inspecting the harddrive before sony touches it to see what can be revcovered.
Also if it is XP you could also try using a regular xp cd and boot to it and see if its possible to do a repair install. But this is only after you connect it to a pc and recover whatever is possible