Itunes invalid signature

Are you getting this error : Windows reports that iTunesSetup.exe is not a "valid Win32 application

If so check out this article : http://support.apple.com/kb/TS1406

2, more detailed descriptions, of the fix here : http://www.zolved.com/synapse/viewcontent/28312/Itunes_Error__iTunesSetup_exe_is_not_a_valid_Win32applicat

and here : http://hubpages.com/hub/itunes-setup-exe-not-a-valid-win32-application-error

edit : If all else fails have a friend download the latest iTunes/Quicktime and burn it to disk for you.

In addition you may want to use the Windows Uninstaller : http://support.microsoft.com/kb/290301
That should give you the necessary basis for a clean install of iTunes software.

Message was edited by: Pamela Gadsden

This invalid sig problem has been a real pain. We suspect that the router is often involved although there are other possibilities.

A few simple things you can try to help isolate the cause of the problem:
Restart your router and your PC.
Try plugging in if you are on wireless.
Check the settings in your router against your ISP's documentation.
Try another browser e.g. firefox or chrome if you are using I.IE.

If you have another PC at your location, can you download a good copy of the iTunes installer with that?

If you are using a laptop, can you take it to another location and try downloading there.

Otherwise can you get a know good copy of the iTunes installer from a friend?

After thought: search for posts by bnoir who has been doing a lot of work on this.

Message was edited by: polydorus

If you are having a wider problem with digital signing, it would be a good idea to do a scan for malware as that can sometime cause problems with cryptographic services.

Also run through *Method 4* in this link:
http://support.microsoft.com/kb/822798

It ensures that all the relevant dlls are registered and also if there are error messages that can help. If you are using Vista you will get not found messages on 3 dlls as they are not present in Vista -initpki.dll gpkcsp.dll slbcsp.dll

You should be able to use copy and paste on the individual lines so save typing and for accuracy.

Problems with these dlls are much more common with XP than Vista.

If the copy from your friend runs then you may want to get a different router.
Was this one from your ISP when you got braodband?
If not what did you buy ?

+I've already ran windows defender and it said there was no malware or spyware on my system.+

I am afraid Windows Defender is not adequate, do you have any other security software?

You could run an on line scan, several of the big names provide free scans e.g. Norton, Kaspersky, pandasoft. Stick to a big name, there are many scams out there.


It would also be helpful to know more about your system.
operating system, security software, router make & model.

Posting the full results of the iTunes Network connectivity tests also provides a lot of information. You can copy&paste the results.

(iTunes>>Help>>Run Diagnostics>>Network Connectivity tests)