Be very very careful about uploading new versions of anything.
I know someone who lost his entire music catalogue of 5 or 10 thousand tunes when he tried to (as prompted by his 'puter) install a new version of i-Tunes.
He had a pc. Apple may not want to be compatible with microsoft windows pc?
You'll need to input whatever you've collected on iTunes to memory sticks, a cheap portable hard drive or your iPod, then when you know you're safe, download the new vers of whatever it is you're aiming at.
That download you're attempting is perhaps subversively and wrongly telling you you need to buy yet another new computer? Good luck
xL