Database Performance Hit

It's like I have gone back to my working days. My stamp database is unresponsive for minutes at a time. This also happened a couple of weeks back but the problem went away. It started again today. Even after a reboot and with just the Access database running, the Unresponsive Message comes up.  This is generally caused by a background program taking resources.  I now have task manager running and performance graphs running and CPU totals coming up and I can't see the issue.  While I was typing this, the database came back with fast response again. It's current size is at only 10000 records and can easily go past 100000 in an Access database.  I will have to get the analysis graphs up quicker next time it happens.  There will be a next time.