In the early DOS (Disk Operation System) environment there was a tool called CHKDSK (Check Disk). This checked the hard drive for errors and displayed a status report. This is a useful tool at times. Type CHKDSK at any DOS command prompt and you will see the following:

With the advent of Windows 95, etc. CHKDSK's throne was usurped by SCANDISK. SCANDISK is a more thorough hard drive error checking device.

PC History: In the beginning, there was DOS. This confused most people. DIR, XCOPY, EDIT, ATTRIB, etc. Everyone is speaking in tongues!? Then there was a shell that laid on top and gave us a better visual form of navigation. This was Windows 3.1. This was certainly limited but much more "user-friendly". DOS at the base, and Win 3.1 fitting over the top like a visual glove. Then there was Win 95. This integrated DOS and Windows together. Although they are essentially different entities, now we can no longer install some version of DOS and put Windows on top. The version of DOS you are going to end up using COMES with Windows 95. This was a brand new world. In this new world the BOOT process has changed a bit. It became more critical that everything initialized properly and shut down correctly. With everything tied together things became more wobbly. And one of the wobbly fix-it tools is SCANDISK.

When your Windows 95/98 computer starts up it runs specific initialization routines and startup functions. It wants to finish things up to feel comfortable about itself. It's like this: If we call OFF (A) and ON (B) then we could say this. Windows toggles between A and B, and B and A. If somewhere it gets interrupted between points and gets caught in the middle, or crashes, it doesn't know what to do. And if it gets lost in the midst of its own instruction sets it tells us that the best thing for it to do is to use SCANDISK and make sure there are no errors or lost data fragments on the hard drive. If there is none, then it will make another attempt at starting up.

When you shut your computer off, Windows 95/98 tries to make its travel plans from B to A. Did it make it? If it did you will see a message that says "It is now safe to turn off your computer". If it didn't, and hangs on the penultimate Windows screen, or the BSOD, then it didn't make it's destination. It will probably run SCANDISK when it starts again. 

This is a safety feature. It is generally good. However, it is often a pain to have to wait for it to scan all the time if you are having "shut-down" problems or crashing issues.

If SCANDISK does find an error, it will prompt you to fix it and offer you the option of recording the fix so you can UNDO it if necessary. It's up to you. Do you want to ability to UNDO it? If you don't, then select DON'T FIX. Then it will create a file, or series of files, on the root of your C: drive called FILE0001.CHK, 2, 3, etc. These are our lost data fragments. If everything works fine we can delete these some day.

On startup the SCANDISK routine looks differently than if we ran it from within Windows. On startup it is a blue screen with a yellow bar sweeping across the bottom. To run it from Windows, you will usually find it somewhere in the ACCESSORIES program menu.

When you select SCANDISK it will look like this:

You can select what drive you want to check as well as set advance options. It is useful to know that this tool is available if you have disk problems. Also know that if you see this on startup, it is only trying to make sure things will be alright when it makes it journey from A to B. 

If it comes on all the time on startup, you have other things to deal with, like something hanging on and not shutting down correctly. This may be able to be addressed with the TASK MANAGER.