I'm running Windows 7 Home Premium 64-bit and am having difficulties with Windows Back-up, the use of which always leads to Error 0x81000038. Following Microsoft's guidance, the first step is to open the Registry and take a look at HKEYCURRENTUSER\Software\Microsoft\Windows\CurrentVersion\Explorer\ShellFolders where (in my case) one finds that the "Data" column for "Appdata" is blank. According to Microsoft, this is the root of the problem.

Following from this, one opens up the command prompt function and types in "set Appdata", which returns the result (in my case) "C:\Users\Stephen\Appdata\Roaming". [I am the sole registered user and Administrator.]

The actual cure should now be simple - copy the result from the command prompt and paste it into the erroneously empty space in the Registry "Data" column detailed above. Here, I'm already out of my comfort zone, so it is a set-back to find that there is no "copy" function in the command prompt area - though there is a "mark" function which seems to have no effect beyond enabling one to highlight the returned string. Optimistically, I now assumed I could simply type the required string into the Registry but found I was unable to gain access to the (empty) line in the "Data" column after selecting "Appdata".

I have read the Registry's "Help" files but they don't seem to cover my problems and they aren't written for novices like me. Probably, I should now leave well alone before I do some serious damage - but I hate having to admit defeat (even though I have Paragon's freebie back-up & restore software to use in lieu of the Windows function); but the unsolved problem would always be nagging me!

If anyone could tell me what I'm doing wrong and describe the correct procedure (in really simple terms, please!) I would be most grateful.