I tried to download three updates using Apple Software Update and neither iTunes or Quicktime would install because of an "invalid signature." Then, I tried installing manually, and it still would not work. Anyone? Anything? Help!
I had the invalid signature problem also and was able to fix it. I went to my add remove programs in windows XP. I clicked on Apple software update program and you have 2 choices either change or remove the program. Click change program it will come up with a box that says repair click the box, it should say the program was repaired. Exit add remove programs and go to iTunes and try the update again. Hopefully it will work for you too. Good Luck!!
Just doublechecking something ... you were getting your "Invalid Signature" message while doing a download of an update using Apple Software Update, rather than downloading an installer directly from the Apple website?
I have a Win machine on which I occasionally use Quicktime, and when I run Apple Software Update it says I have two updates available, Quicktime 7.3 and iTunes+Quicktime 7.5. When I attempt these updates, auto or manual, I get the "invalid signature" messages, with the comment "It will not be installed" (auto) or something like "It will be deleted" (manual). I don't understand the question about "not connecting directly to Apple" -- my assumption is that it IS going directly to Apple (it doesn't say). Using the "repair" option in ASU in the Control Panel doesn't fix this. Any more suggestions?
Well, a window for Apple Software Update popped up (don't think I've ever seen this before...or at least not for a long time) with the same two updates, and this time they went through with no complaint about the signature (you can watch the process, somewhat, by having \Documents and Settings\NetworkService\Local Settings\Application Data\Apple\Apple Software Update in an open window). So, maybe the tip worked after all.