Cannot add artwork from computer to itunes 12.1

Question

I can add add artwork from itunes store but most of my collection are old and itunes cannot find them. I have loaded them onto Helium ( It found them) But I cannot get them in itunes. Add artwork way, Copy and paste, Drag them Nothing works.

Answer 1

iTunes 12.1 should support three ways to add artwork using existing image files on your PC, all starting with right-click > Get Info and then the Artwork tab,  Then:
click the Add Artwork button, navigate to and select an image file on your computer, or
drag and drop an image file from your computer to the Artwork tab, or
copy an image to the clipboard, for example, from a web page, go to the Artwork tab and press Ctrl-V (the right-click > Paste option that was available in prior releases is not available in iTunes 12.0 or 12.1)
However, there are three cases in which you can follow these procedures but artwork is not correctly associated with or embedded in your media files:
your media are in a format that doesn't accommodate embedded artwork - typically WAV files.  To embed artwork you'll need to convert to another format - Apple Lossless or AIFF if you want to preserve lossless quality, AAC or MP3 otherwise.
your media files are read only - to fix this, use Windows Explorer to find the folder that contains your files, right-click and select Properties.  On the General tab there's a check box labeled "Read-only" - if this is checked, or is grey (sometimes blue), click the box so that the flag is unchecked and the box is white.  Click OK, and then OK again when the "Apply changes to this folder, subfolders and files" option selected.  Now try adding the artwork again.
Windows permissions issues are preventing iTunes from updating your media files (there's some anecdotal evidence of a change in this behavior in iTunes 12).  See turingtest2's notes on Repair security permissions for iTunes for Windows for advice on fixing this, then try adding the artwork again.