This error is likely caused by one of two things, though neither of them is really hinted at by the error description:
- The program you're trying to update is already running, and therefore the updater cannot modify it.
- Your antivirus software is detecting the tool as malware. This often happens with advanced tools, especially in the case of password recovery tools.
In my particular case, it was a little of both.
For Process Explorer, it was reason #1. I like to keep Process Explorer running in my system tray on startup, so it's most likely running whenever I check for an update as well.
For the password recovery tools, it was #2. I checked the logs of the Antivirus software, and saw that all the tools I was having problems with (except Process Explorer) had been flagged with things like "Hacktool" or "Trojan.Gen" - some signatures even had the program's actual name. All of them had been acted upon in some way: Deleted, Quarantined, or just "Access Denied".
How do you fix this?
Well, #1 is easy. Just exit the tool before you update, and re-run it if desired after updating is complete.
The #2 cause isn't so easy if the system isn't yours. If it is yours you can either choose to use an Antivirus program that doesn't consider your tools as malware, or set your Antivirus program to ignore them. If it's not your system, then you may not be able to make these modifications. If you really need the software, you'll have to go through whatever process your organization has in place for whitelisting such tools.
If you don't really need the software, and just want to get rid of the errors, you can disable updating for the offending tool and hide it from the list. Right-click the tool in WSCC, and select Properties. Then go to the Options tab and select "Don't show in the list". To un-hide the item, you'll have to reverse the process but remember to show hidden items first.