Hard disk drives do not last forever. There comes a time when you simply need something bigger.
Even the most experienced computer hacks may find opening the computer case and fitting a new disk drive a daunting experience.
Step, by step, we take you through the basics of fitting a new Enhanced-IDE (EIDE) drive, highlighting a few of the pitfalls: Back up your files.
The first thing you should do before you start tampering with your hard drive is to back up your data.
Often the new hard disk or your operating system includes disk management software that makes this part of the job easier.
For instance, Windows 95 includes BackUp, a utility for copying or backing up files, directories or hard drives.
If you decide to reinstall your operating system and applications from scratch, at least make a copy of your files.
Also, it is wise to make a boot disk containing the normally hidden system files essential for getting the new drive up and running.
To do this, insert a floppy disk and at the Dos prompt type: FORMAT A: /S Unfortunately this is rather a crude method, copying only a few of the files required. You will need to separately copy the Config.sys, Autoexec.bat, and utilities such as FDisk and Format.
Finally, be sure to keep a copy of the CD-Rom device driver on hand - you are going to be really stuck if your operating system and applications are on CD-Rom and the drive will not run.
Inside the PC - a few preliminary checks.
Before you get physical, make sure you have a Phillips screwdriver, a bowl for the screws, and labels if you are not sure where all the different cables should go.
Disconnect the computer from its power supply, lift the lid and take a long look.
If this is to be an extra drive, do you have a spare four-pin power cable from the power box? If not, buy a power cable splitter - this shares the power from an existing lead to another peripheral.
Check the signal strap is long enough to reach from the drive to the motherboard or second disk drive.
Drives are getting smaller and if the form factor is different to the old model, check you have the correct rails to secure the new device within the bay.
Now you can start to remove all the connectors and unscrew the drive from the rails.
For straight swaps the procedure is fairly straightforward, with little need to change the pins - known as jumpers - on the drives.
However, if you plan to run the new hard drive alongside the existing one, decide which will be the primary (or master) and secondary (or slave) drive, then set the jumpers on both drives accordingly.
The drive installation manuals should show you how to make these changes.
When you re-connect the power cable, the four-pin configuration of the connector makes it virtually impossible to get it wrong.
The 40-pin EIDE is not so simple, however, as you need to match pin number 1 with the correct hole on the connector.
Unfortunately, pin number 1 is not always clearly marked on the drive, although some connectors have notches on the top to ensure they are fitted the right way.
Sometimes there is a red line down the left hand of the EIDE strap, the same side as pin number 1, again to help you hook up correctly.
You will need to connect the strap from the drive to the motherboard via a disk controller card or, with some of the newer motherboards, a connector on the board itself.
For example, Pentium boards have two EIDE channels built in, but if you have an older IDE board you will need to buy an extra EIDE card.
Finally, before hitting the power button, check all connections to ensure everything is securely in place.
Do not replace the computer lid until you are satisfied the disk is working.
Formats and partitioning.
Everything appears to be working and connected correctly, now you need to make sure the PC knows the kind of device you have installed.
This is done by entering specific drive information via the basic input/output system (Bios) set-up program.
You will find this technical nitty gritty either in the drive manual or on the hard drive casing itself. Once you have done this you can go on to Format and partition the hard disk using the fixed disk set-up software included with the drive or Fdisk on the boot disk you made earlier.
To do this, insert the boot disk into drive A: and restart the computer. At the prompt, type FDISK C: making at least one boot partition on your drive. Then type FORMAT C: /S to copy the system files to that hard-drive partition, making it bootable to Dos.
At this point you should now have a familiar C: prompt, allowing you to install your CD-Rom Drive device driver, operating system and other software.
SOME USEFUL WEB SITES Most drive vendors post individual drive specifications together with other excellent bits of product information on-line.
Also, some of the extensive FAQ sections and newsgroups may hold a quick solution to that gritty problem you've been puzzling over for ages, and shouldn't be ignored. Good starting places include: Conner: www.conner.com  IBM: www.ibm.com  Maxtor: www.maxtor.com  Microsoft:www.microsoft.com  Quantum: www.quantum.com  Seagate: www.seagate.com  Western Digital Corp: www.wdc.com