CompTIA A_ Certification All-In-One Exam Guide, Seventh Edition - Michael Meyers [197]
EXPAND e:\I386\*.CAB -F:OLEPRO32.DLL
EXPAND goes through all of the CAB files and finds the file. If you want to see details on the EXPAND command, use Windows Help or type EXPAND /? at a command prompt.
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NOTE Chapter 15, “Working with the Command-Line Interface,” goes into a lot of detail on using the command line.
Corrupted Data on Bad Sectors If the same errors continue to appear after you run the disk-checking utility, there’s a chance that the drive has bad sectors.
Almost all drives today take advantage of built-in error correction code (ECC) that constantly checks the drive for bad sectors. If the ECC detects a bad sector, it marks the sector as bad in the drive’s internal error map. Don’t confuse this error map with a FAT. The partitioning program creates the FAT. The drive’s internal error map was created at the factory on reserved drive heads and is invisible to the system. If the ECC finds a bad sector, you will get a corrupted data error as the computer attempts to read the bad sector. Disk-checking utilities fix this problem most of the time.
Many times, the ECC thinks a bad sector is good, however, and fails to update the internal error map. In this case, you need a program that goes back into the drive and marks the sectors as bad. That’s where the powerful SpinRite utility from Gibson Research comes into play. SpinRite marks sectors as bad or good more accurately than ECC and does not disturb the data, enabling you to run SpinRite without fear of losing anything. And if it finds a bad sector with data in it, SpinRite has powerful algorithms that usually recover the data on all but the most badly damaged sectors (see Figure 12-70).
Without SpinRite, you must use a low-level format program supplied by the hard drive maker, assuming you can get one (not all are willing to distribute these). These programs work like SpinRite in that they aggressively check the hard drive’s sectors and update the internal error map. Unfortunately, all of them wipe out all data on the drive. At least you can use the drive, even if it means repartitioning, formatting, and reinstalling everything.
Dying Hard Drive
Physical problems are rare but devastating when they happen. If a hard drive is truly damaged physically, there is nothing that you or any service technician can do to fix it. Fortunately, hard drives are designed to take a phenomenal amount of punishment without failing. Physical problems manifest themselves in two ways: either the drive works properly but makes a lot of noise, or the drive seems to disappear.
Figure 12-70 SpinRite at work
All hard drives make noise—the hum as the platters spin and the occasional slight scratching noise as the read/write heads access sectors are normal. However, if your drive begins to make any of the following sounds, it is about to die:
Continuous high-pitched squeal
Series of clacks, a short pause, and then another series of clacks
Continuous grinding or rumbling
Back up your critical data and replace the drive. Windows comes with great tools for backing up data.
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NOTE Most hard drives have three-year warranties. Before you throw away a dead drive, check the hard drive maker’s Web site or call them to see if the drive is still under warranty. Ask for a return material authorization (RMA). You’ll be amazed how many times you get a newer, usually larger, hard drive for free. It never hurts to check!
You’ll know when a drive simply disappears. If it’s the drive that contains your operating system, the system will lock up. When you try to restart the computer, you’ll see this error message or something similar to it:
No Boot Device Present
If it’s a second drive, it will simply stop showing up in My Computer/Computer. The first thing