Without system info nobody can help you. these could be mundane permissions/ user privilege issues that prevent creation of new files/ folders out of the current user's security context just as this could be performance issues with your drives getting full or external tools interferring. whatever. We simply can't know.
Windows XP previously, Windows 7 now (has been for about a year).
Computer is according to 'device and printers', ACPI x86-based PC, with Intel Core i5-3450 CPU@3.10Ghz, and Xeon processor E3-1200 v2/3rd Gen Core - was all put together last year.
Drives are nowhere near full.
Only recent update has been Java on the weekend, coinciding with when I first noticed the issue.
I have deleted Photoshop 7 off the computer using Windows 7's delete program function as there is no uninstall.exe file in the PS7 folder. I deleted it out of Startup and off the Desktop. I also deleted the remaining plugin folder containing Noise Ninja anti-noise software.
I reinstalled the PS7 software again and in PS7 I expected the batch processes now to only contain the default batch processes, but all of my created ones are there in the list - this says they are not deleted in the uninstalll process. Where are these stored on your computer so I can delete these perhaps? However I am unconvinced that will actually achieve anything (see * below). I deleted a few of these using the trashbin off the Actions palette.
I created the numerous variations of the batch processes again, with 'save as overrides' box checked/unchecked and still no joy. What I have noticed it does not matter whether you used 'save as' as one of your actions it has replaced it with 'save' every time (*). How does/can that happen? All the other 'save' actions for any of the other batch processes all show as 'save' now. There is of course no option to change the 'save' in the actions to 'save as', eg right click mouse or something.
I haven't found anything related in Google searches.
Could you post a screenshot of one of the actions and a screenshot of the settings your using in the batch dialog?
(with all the steps in the action open)