No I normally leave the system on 24-7. It got a BSOD overnight after running continously for several days. It was when I attempted to reboot that I discovered that the system could not retrieve data from the drive. The SCSI controller reports that the device doesn't respond, and it has not responded at any time for a whole week. It won't even report the drive capacity at boot up when the SCSI controller polls all the devices on the SCSI chain.
Microsoft SCANDISK is rather amateurish compared to Gibson Research's Spinrite 6.0. If you have a file with data on marginal sectors, Spinrite can retrieve most or all of the data. In fact, I would strongly urge anyone who has data on a fragile hard drive not to use SCANDISK, because it will find bad sectors on the drive, report them to the hard disk, and cause the disk to replace the sector with a replacement sector before copying the contents to another location. This means you can permanently damage a file that occupies just one bad sector using SCANDISK. Spinrite will use heroic measures to retrieve data, and it will save every bit that it can read and save it to good portions of the hard disk before instructing the hard disk to permanently mark the sector as bad.
If Scandisk reports surface flaws you might as well pitch the drive as the drive surface can only get worse.
Spinrite can als be used for routine low level maintenance of hard drives. It installs itself with its own DOS compatible operating system onto bootable floppy drives and USB thumb drives. It will safely copy data from sectors to be tested to known good sectors of the drive. Then it will do extreme pattern testing of each sector to determine how reliable it is. Sectors that don't pass the tests are then marked as bad. One really good thing about Spinrite is that it rewrites every bit on the hard drive, refreshing the magnetic signals encoded on the drive. This is especially good, because very important sectors such as the partition table very rarely get written to causing the signals to fade over time.