Whether it was dropped, overheated or died of old age, the hard drive is possibly the most failure-prone part of your PC.
Your PC problems solved
If the drive spins but behaves erratically, you probably have data corruption caused by a failing drive. Try the following steps to recover and copy your data before the bad drive dies.
If you're using an IDE drive, check your data cable is connected properly. If it is, try a new cable. IDE cables are cheap and prone to having their insulation stripped by the metal edges inside a PC case, shorting the cable.
Try booting with a Knoppix CD or another boot disk to find out whether the drive is readable. If it is, back up the data to another drive and reformat the original disk.
You may have bad sectors; try using HDD Regenerator (dposoft.net) to locate any. Download the demo and burn it to a bootable CD. If the free demo finds bad sectors, it's probably worth paying for the full version to recover the bad sectors and make the drive usable.
TackTech's website features manufacturer-specific utilities for virtually any hard drive. Find out which company made the drive that's failing, then download the appropriate diagnostic application. These free tools can be a major help in diagnosing problems on a drive and repairing them. The Hitachi, Western Digital and Seagate tools (in that order) will best work on other manufacturers' hard drives.
If the hard drive will not spin at all, you can still try a few tricks to revive it.
While ensuring you don't tap or whack it (which will cause data loss), hold the drive in your hand and rotate your arm outwards quickly, parallel to the orientation of the platters – as if you were throwing a Frisbee. Repeat several times. Make sure not to bang the disk on anything. This may just solve a problem known as ‘stiction' (static friction), which can prevent drive platters spinning.
Try attaching the drive to a high-wattage power supply. The extra burst of juice could jar it into spinning up one last time.
The 'freezer trick' is an old standby if you have a drive that is clicking but not spinning: Put the drive in a plastic freezer bag – and wrap it in a paper towel for extra protection against moisture – to keep water out.
Freeze it for a few hours. Let it thaw back to room temperature after you take it out. Mop up any condensation you see. There's no agreed-upon length of time to freeze it, but start with an hour and work your way up to 24 hours to see whether you can make the drive spin up one last time.
Remember that if you do get a dead drive spinning, don't let it stop until you've copied all your data. It's unlikely to work twice.
If all else fails and you need data off the hard drive, your last, best hope is to send it to a data-recovery service such as Ontrack (ontrack.co.uk) or DriveSavers (drivesavers.com). It isn't cheap, but it may be worthwhile.
Hard drive health tips
Ensure your backups are up to date. Mirror a second hard drive so you have a real-time backup with minimal risk of data loss.
A cheaper aid is to monitor your drive's health with the HDD Health utility (panterasoft.com), which can predict most impending crashes.
Locked out of Windows?
If you've lost your XP login password, try logging in under another account with administrator privileges. Any administrator account can reset the password of any other account.
If you're not using the XP icon-led login screen, try logging in with the account named Administrator. But if you're using the XP login screen, try pressing Ctrl, Alt, Delete to reach the old, NT-style screen, which should allow you to type in the username.
If no other account exists on the PC, you'll need a third-party tool such as Ophcrack. Using another PC, download it from ophcrack.sourceforge.net and burn it to a disc. Boot from this CD and watch Ophcrack go to work. Based on extensive password tables, it can recover most passwords in a matter of minutes, for all the accounts on a PC.
There is a tool that can reset your password if everything else has failed. Such tools generally involve a small risk of data loss or corruption, however. Offline NT Password & Registry Editor and Emergency Boot CD both include bootable CD versions, and are fairly self-explanatory if you're comfortable working with the command line.
If you've lost a Bios-level password, try resetting or bypassing it. Try backdoor passwords as listed here. Or try resetting your CMOS, to cause the Bios to reset to its default state.
Whether a corrupt file or a dodgy laptop is at fault, your nerves are shot if you're expected to give a presentation without your slides.
Of course, you could brave it and forgo your pictures. Everyone hates PowerPoint and at least you'll be able to prove your flexibility and ability to handle setbacks if you do without the crutch of slides and continue immediately.
Back in reality, if you have to have a presentation and a quick reboot doesn't help, try OpenOffice. You can download and install it in 10 to 15 minutes. A copy stored on a USB key is a good emergency option that can be used on any PC.
To avoid future presentation dilemmas you should bring printouts of all the slides to use as handouts, and pack the aforementioned OpenOffice Portable as a precaution.