alternate Operating system

Can you install a second operating system on a second hard drive? Yes

The real problem is going to be that unless your friends computer has the EXACT same set of hardware in his computer (CPU, motherboard, video card, peripherals), chances are great that the computer will not boot. The problem is differing device drivers (i.e. You can't load an operating system on a drive installed in a computer with an Intel CPU on a motherboard with a Intel chipset, and expect the drive to boot in a system that has an AMD CPU on a motherboard that has a VIA chipset).

I could not completely agree more. The best thing is to just take that hard drive and stick it in your friend's machine. Then install the OS and programs needed. Never install an OS on a hard drive that will later be the primary boot drive of another system (unless you plan to format the puppy).
Make sure you make yourself a 98 Boot Disk. You will never know when you need it.

Okay, first you get the search thingee on the toolbar up and have it search for 'DOS' at 'Home', select two-byt DOS and then follow directions.
RIVER FREIGHT

I fully agree that you do NOT want to install ANY version of Windows onto a hard drive and then move it to another PC.

Now, you can do the following to make installing Windows on the new PC easier:

Partition and format the drive as desired.
(You will need to run fdisk on the new PC and make the primary DOS partition active.)

Create a folder and copy the Windows installation CD onto the drive.
I use D:\Win98 for Windows 98.

Create 2 more folders and download desired drivers and software updates to these folders.

In the driver folder, create a sub-folder for each device.
Make sure to extract the driver files from their archives.

For W98, install the drive in the target PC.
Boot from the W98 startup floppy.
Run fdisk and make the primary DOS partition active.
Exit fdisk, re-boot if needed.
Execute the system command
sys c:
This will make the hard drive bootable.

Then, browse to the drive and folder that you copied the Windows CD to, and run setup.

When Windows is installing device drivers, point the wizard to the folder where you stored that devices driver files.

Chas

Okay I'm not perfect and I forget stuff sometimes: once you get Two-Byt DOS up and selscted - I thought you got paid the big bucks - hold down control and hit enter on the adding machine face to the right of the typewriter face on the keyboard and then just follow instructions.
WAIT! your in the ARMY, get the correct manual and follow instructions.
RIVER FREIGHT

Yes, you could do the same things for Windows XP.

For XP there is less of an advantage, as XP copies most of the install CD onto the drive by itself.

NEVER install XP and then move the drive to another PC!!

You will at best cause an activation event, and need to call Microsoft to be able to use the PC.

At worst, the PC will not even boot!!!

I normally install XP onto un-partitioned drives and allow the installer to set up a NTFS volume of the size I desire for the boot partition.

Chas

You are in the army.

If you are on an army computer then you get the manuals out and you follow the instructions on how to do this; then you come back to us plebians and tell us how; If it is on your computer then you get out the manuals and follow the instructions and then you come back here and tell us how; Finally you go to see your commanding Officer about the Court Marshal Reveiw that is being scheduled to decide whether or not there are grounds for a court Marshall or one of your supiorers because it is standing order no.4325678113-46281 that you are violating and on it you will also find my name, Guy R Hengst, as one of the signatores; next and last "I" get the big bucks not you.