Downloading purchses say, "stopped (err=.5000)" How can I fix this?

Question

This is the error message I recieve everytime I try to download my iTunes purchases. It says that I do not have access privileges for the operation and to check my connection to the network.
Occasionally cliking retry will eventually allow a song to download, but the majority of purchases have yet to reach my library.
The only help I could find with this problem is for Mac computers, whereas I have a Windows XP. I am hardly computer savvy enough to fix this problem myself, although I have tried removing and reinstalling iTunes with no improvement.
If anybody could please lend their assistance I would greatly appreciate it! Thank you for your time.

Answer 1

With the Error 2, let's try a standalone Apple Application Support install. It still might not install, but fingers crossed any error messages will give us a better idea of the underlying cause of the issue.
Download and save a copy of the iTunesSetup.exe (or iTunes64setup.exe) installer file to your hard drive:
http://www.apple.com/itunes/download/
Download and install the free trial version of WinRAR:
http://www.rarlab.com/
Right-click the iTunesSetup.exe (or iTunes64Setup.exe), and select "Extract to iTunesSetup" (or "Extract to iTunes64Setup"). WinRAR will expand the contents of the file into a folder called "iTunesSetup" (or "iTunes64Setup").
Go into the folder and doubleclick the AppleApplicationSupport.msi to do a standalone AAS install.
Does it install properly for you?
If instead you get an error message during the install, let us know what it says. (Precise text, please.)