Scandisk standard checks the administration of files and where they are and what parts of the disk are still available for new files. After an illegal shutdown, there can be errors in those parts, and then scandisk is run automatically when you boot. It's a good idea to run scandisk before you run defrag, but that's all. Several times a week is very, very frequent, and generally unnecessary. What kind of error triggers you to run it? Either it's the wrong respons to that error, or there's something wrong with your computer, I should say. If you like, tell more about it.
A thorough scandisk checks if all sectors (every square micro-inch so to say) is undamaged, and marks them unusable if they are damaged. You'll lose the information that it contained.
That's a nice function for diskettes (which build up damaged sectors over time), and it's practically never necessary to run on a hard disk. Only when there is a definite reason to do so, which I've never seen in fact. Note the rule of thumb for a hard disk: replace if a thorough scandisk finds errors.
Hope this helps,
I run Scandisk Standard several times a week or if an error pops up (Windows 98), but how necessary is it to run the Thorough, and if it is, how often would you suggest? I mean I don't quite understand. Is it possible that I can have errors on my computer, but Scandisk Standard shows no errors? Thanks