Attachments in Vista / Windows Mail and Windows Live mail

I'm trying to get mail clients working in a Vista SP2 32-bit machine. When trying to save attachments in either Windows Mail or Windows Live mail, it fails in both programs. In Windows Mail, attempting to open the attachment directly results in no response at all-- no error, no effect. Trying to save the attachment gives an error of "The command failed to execute." Attempting to save all attachments at once gives an error of "There was an error saving one or more of the attachments. Please check your free disk space and try again."

In Windows Live mail, opening the attachment directly also gives no effect. Trying to save attachments individually, after browsing to the save location, the attachment is not saved-- no error message. Attempting to save all attachments gives the error message "There was an error saving one or more of the attachments. Please check your free disk space and try again."
However, if I drag the attachment directly from the email to another folder, it is saved correctly.

I've checked and double-checked for malware, removed and reinstalled antivirus software (AVG Free 8.5), uninstalled and reinstalled IE8, checked Security setting in Windows Mail for attachment security, even removed and reinstalled Windows Live Mail, all with no effects.