Hard drive dying

This pertains to my Windows 95 machine which I still use. Last Fall I was
booting the computer and it beeped and said there were possible errors on the
disk and I had to run a thorough scan to check the drive. It found one bad
sector. I rebooted the computer and it ran scandisk again and found another
bad sector. It was okay until this Spring when it found another bad sector.
Now yesterday and today it found two more bad sectors.
I've had the computer for seven years and have always made it a habit to run a
thorough scandisk and a defrag on a regular basis. I have a few questions.
First, based on your experience and the fact that scandisk is only finding one
or two errors at a time how much longer do you think the drive is going to
last?
Second, it takes scandisk at least 30 minutes to complete a scan, and that's if
it doesn't find any errors. If more disk errors pop up during a boot sequence
is it safe to stop scandisk and let Windows finish booting up and then run
scandisk at a more convenient time?