I forgot to mention I have run several virus scans with differing programs and a malware scan, all negative.
My 8yr old Dell laptop contains a 500mb hard drive. Upon startup, file explorer shows, say 40 gb of free disk space. Gradually, even with no active user input, Windows 10 will gradually report less and less free space, until eventually, in less than 1/2 hour, it says I have very little or no free space. This causes any software program temporarily needing free space to behave as if there is no free space. If I then reboot, Windows will report another larger amount of free space, but never the same as the amount shown after the previous reboot. Then the cycle repeats itself. Any ideas? This is a royal pain.