ITunes 10.5 won't run after accepting license agreement

Question

I've been searching message boards for the past 2 days trying to figure out what's going on but have found nothing. I'm running Windows XP Pro. I updated to iTunes 10.5 only so I can update my iphone to IOS5. The install went fine without any errors. When the installation was complete, I double clicked to load iTunes 10.5 and it opened up the software agreement screen, I clicked agree and then agreement window disappears and then nothing, just nothing... 
I have done this several times. I've uninstalled itunes and reinstalled itunes, still the same thing. Then I went drastic and I uninstalled every single bit of apple software on my computer and then downloaded new versions from the apple site and reinstalled everything only to get the same result! No matter what I do, everytime I try to run iTunes 10.5 it only opens the software license agreement screen and does absolutely nothing once you click "accept."
I've looked at all of the processes running and itunes appears in the process list once I run it but then after I agree to the license agreement, it dissappears from the process list after a few seconds.
This is ridiculous.

Answer 1

Blocked by configuration: (Mac OS X/Windows)
Configure Internet Options (for Windows computers only):
Run iTunes Diagnostics. If the "Secure link to iTunes Store" section does not pass, do the following.
Open Internet Explorer.
From the Tools menu, choose Internet Options.
Click Connections.
Under "Dial-up and Virtual Private Networking," choose "Never dial a connection." It may not be possible to choose this if you’ve never used dial-up Internet; if this is the case, skip to the next step.
Click LAN Settings.
In the window that opens, enable the option to "Automatically detect settings" if it is not enabled.
iTunes uses Internet Options proxy settings. Apple recommends removing proxy settings that interfere with access to the iTunes Store if needed.
Click OK.
Click the Advanced tab.
Scroll down to the Security section and look for the option to "Check for server certificate revocation." If it is enabled, disable it.
Look for Use SSL 3.0 and Use TLS 1.0. Make sure at least one of those two checkboxes is selected and click OK (You can select both checkboxes).
Apply any changes, and restart your computer if you modified the option to "Check for server certificate revocation" (step #11).
Rebuild network information.
WindowsWindows XP:
From the Start menu, choose Run.
In the Open field type cmd and click OK.
In the resulting window, type ipconfig /flushdns and press Return on the keyboard.
You should see a message that the DNS Resolver Cache has been successfully flushed.
Windows Vista and Windows 7:
From the Start menu, choose All Programs > Accessories and then right-click Command Prompt and choose "Run as Administrator" from the shortcut menu. If Windows needs your permission to continue, click Continue.
In the resulting window, type ipconfig /flushdns and press Return on the keyboard.
You should see a message that the DNS Resolver Cache has been successfully flushed.
The hosts file may also be blocking the iTunes Store.
If you want to have Windows try to restore the hosts to default, follow the "FixIt" in How do I reset the hosts file back to the default?.
Note: Work systems may put information into the hosts file. Consult whomever is responsible for supporting Windows on your system before resetting the hosts file to default.
If restoring the defaults did not resolve the issue, you can find your hosts file at C:\WINDOWS\SYSTEM32\DRIVERS\ETC .
Select the hosts file. Choose Edit > Copy, and then choose Edit > Paste.
There should now be a duplicate of the hosts file named "Copy of hosts" (Windows XP) or "hosts -Copy" (Windows Vista/7).
Drag the original hosts file to your Desktop. If Windows needs your permission to continue, click Continue.
Drag the "Copy of hosts" (Windows XP) or "hosts -Copy" (Windows Vista/7) to the Desktop.
Right-click "Copy of hosts" (Windows XP) or "hosts -Copy" (Windows Vista/7) and choose Open. You may be prompted to choose the program you want to use to open this file. Double-click Notepad.
When Notepad opens, choose Edit > Select All, and then choose  Edit > Delete.
From the File menu,choose Save. Quit Notepad.
Drag the "Copy of hosts" (Windows XP) or "hosts -Copy" (Windows Vista/7) file from your Desktop back into the original location (given in step 2). If Windows needs your permission to continue, click Continue.
Right-click the  "Copy of hosts" (Windows XP) or "hosts -Copy" (Windows Vista/7) file, and choose Rename. Type "hosts" (without quotation marks) and press Enter.
Restart your computer and try connecting to the iTunes Store.