Computer does not recognize iPad

It happened last month when I helped my relative to connect an iPad to a computer. Though they had tried every way, I found the solution was quite simple.
iTunes may prevent a computer from recognizing an Apple device if the iTunes' Apple ID is different than the device's Apple ID. So just log out that account in iTunes.

Checking for Updates Stuck in Windows 8.1

Also, in "Control Panel\All Control Panel Items\Troubleshooting\Fix problems with Windows Update", received this after scanning:
"windows update error 0x80070490" ...... fixed (actually it's not fixed)

After searching for solutions online for a while, there is a simply fix for this problem. Use the link below, download and install KB3172614:
http://www.catalog.update.microsoft.com/Search.aspx?q=3172614

By the way, these solutions are useless to me:

• WSUS Offline
• WindowsUpdateDiagnostic.diagcab
• sfc /scannow
• Delete "SoftwareDistribution"
• ....

Update:
KB3172614 may get stuck just like the Windows Update does.
I tried several more computers with this problem. Though I solved all of them, it seems I have to use these solutions as a combination. Here are the solutions, and no more than these :)

• use "Fix problems with Windows Update" in Control Panel
• download and run "WindowsUpdateDiagnostic.diagcab"
• delete everything in "SoftwareDistribution" folder in C:\Windows\   
• use "Disk Cleanup" for C:\ and then, click "Clean up system files"   (this may take long)
• install KB3172614  

Try the first 4 solutions again and again in different orders until you can install KB3172614 smoothly. And better install it when the "SoftwareDistribution" folder is empty.