Missing or Default Icons

Please help me: I needed space on my C: drive (an SSD) so I cut the Windows\Installer file, pasted it to D: drive, did what I needed to do with the extra space (install a program) and copied the Installer file back. No problem, I thought, until I discovered that all the icons for Microsoft Office, Adobe Acrobat, Nero, Skype, Itunes and a few others were all gone and replaced with generic ones. I have tried all the fixes listed above and still the same. I even deleted all the User Choice registry keys from each and every file association with no luck. Any suggestions would be gratefully received. With thanks Stephen