I am having many of the issues everyone else has stated. iTunes takes about ten minutes to open. After it opens, unable to connect to iTunes or app stores. Can't update latest versions of apps updates because of this. Removed iTunes and reinstalled. Still the same. I contacted Apple support through email. Finally received an response. The standard basic first steps most of us try before reaching out for help: make sure Windows has the latest updates, make sure you are installing the latest iTunes update, remove iTunes and reinstalled, turn off your antivirus, so on and so on. I have not seen any of the suggestions others have provided that has helped anyone.
In iTunes I went to the help menu and clicked on Run diagnostics. Only checked the "Network connectivity test". Have an red dot next to "Secure link to iTunes Store failed". Clicking on the Help button next to it takes you to a blank Help screen. You click Help again and iTunes usually closes. Clicking on the next button will allow you to copy the Diagnostics test. I do not know what all the information means but I think there is something in there that might be causing the problem (like something under the "**** Runtime Libraries ***" or another area is missing or needs deleted). Since I can't connect to the iTunes store that might be why iTunes is taking so long to load and not working properly. The forth to the last line on the diagnostics test reads "Basic connection to the store failed." I have checked my firewalls and they are open to let Bonjour and iTunes connect. I going to post my diagnostics results. If you see REMOVED in the line, well I removed that information just in case of possible security reasons. Sorry so long. Hopefully someone understands this stuff better than myself and can help iTunes work again. Here the diagnostics:
Microsoft Windows 7 x64 Home Premium Edition Service Pack 1 (Build 7601)
Gateway ZX6900
iTunes 12.6.0.100
FairPlay 2.12.8
Apple Application Support 5.4.1
iPod Updater Library 12.0
CD Driver 2.2.3.0
CD Driver DLL 2.1.3.1
Apple Mobile Device 10.3.1.2
Apple Mobile Device Driver 1.67.0.0
Bonjour 3.1.0.1 (333.18)
Gracenote SDK 3.06.1.3084
Gracenote MusicID 3.06.1.3084
Gracenote Submit 3.06.1.3084
Gracenote DSP 3.06.1.3084
iCloud for Windows 5.2.2.87
iTunes Serial Number REMOVED
Current user is not an administrator.
The current local date and time is 2017-03-30 17:28:35.
iTunes is not running in safe mode.
WebKit accelerated compositing is enabled.
HDCP is supported.
Core Media is supported.
Video Display Information
Intel Corporation, Intel(R) HD Graphics
**** Runtime Libraries ****
c:\windows\system32\msvcp140.dll: 14.0.23918.0
c:\windows\system32\vcruntime140.dll: 14.0.23918.0
c:\windows\system32\ucrtbase.dll: 10.0.10586.788
c:\windows\system32\msvcp100.dll: 10.0.40219.325
c:\windows\system32\msvcr100.dll: 10.0.40219.325
c:\windows\system32\msvcp120.dll: 12.0.21005.1
c:\windows\system32\msvcr120.dll: 12.0.21005.1
**** External Plug-ins Information ****
No external plug-ins installed.
Genius ID: REMOVED
Bonjour service 3.1.0.1 (333.18) is currently running.
iPodService 12.6.0.100 (x64) is currently running.
iTunesHelper 12.6.0.100 is currently running.
Apple Mobile Device Service service 3.3.0.0 is currently running.
**** Network Connectivity Tests ****
Network Adapter Information
Adapter Name: REMOVED
Description: Kaspersky Security Data Escort Adapter
IP Address: REMOVED
Subnet Mask: REMOVED
Default Gateway: REMOVED
DHCP Enabled: Yes
DHCP Server:
Lease Obtained: Wed Dec 31 18:00:00 1969
Lease Expires: Wed Dec 31 18:00:00 1969
DNS Servers:
Adapter Name: REMOVED
Description: Microsoft Virtual WiFi Miniport Adapter
IP Address: REMOVED
Subnet Mask: REMOVED
Default Gateway: REMOVED
DHCP Enabled: Yes
DHCP Server:
Lease Obtained: Wed Dec 31 18:00:00 1969
Lease Expires: Wed Dec 31 18:00:00 1969
DNS Servers: REMOVED
Adapter Name: REMOVED
Description: Intel(R) 82578DC Gigabit Network Connection
IP Address: REMOVED
Subnet Mask: REMOVED
Default Gateway: REMOVED
DHCP Enabled: Yes
DHCP Server: REMOVED
Lease Obtained: Thu Mar 30 17:18:58 2017
Lease Expires: Wed Dec 31 18:00:00 1969
DNS Servers: REMOVED
Adapter Name: REMVOED
Description: Ralink 802.11n Wireless LAN Card
IP Address: REMOVED
Subnet Mask: REMOVED
Default Gateway: REMOVED
DHCP Enabled: Yes
DHCP Server:
Lease Obtained: Wed Dec 31 18:00:00 1969
Lease Expires: Wed Dec 31 18:00:00 1969
DNS Servers:
Active Connection: LAN Connection
Connected: Yes
Online: Yes
Using Modem: No
Using LAN: Yes
Using Proxy: No
Firewall Information
Windows Firewall is on.
iTunes is enabled in Windows Firewall.
Connection attempt to Apple web site was successful.
Basic connection to the store failed.
The network connection timed out.
Connection attempt to Gracenote server was successful.
Last successful iTunes Store access was 2017-03-21 15:25:34.