"My sister lost her systems disc and her HDD failed on her. She's going to ship me her computer and I was going to install a new HDD and Snow Leopard onto it from the system disc/upgrade disc that I got when I ordered my MBP in mid 2009 and got the 10 dollar upgrade to Snow Leopard for buying a new system.
What happens if I use my systems discs on another Mac? Will there be a problem?"
There might be a problem, but then again, if you do things right, there might not be.
VERY IMPORTANT QUESTION:
Does the Mac she's sending you have firewire?
If the answer is YES, the following might help:
You might be able to boot HER Mac into "firewire target disk mode" and then install a clean system to it. Try this:
1. Have the two Macs side-by-side, and have a firewire cable at-hand
2. Power down BOTH Macs completely, ALL THE WAY OFF.
3. Connect the firewire cable
4. Power up HER Mac, and IMMEDIATELY hold down the "T" key, and KEEP HOLDING IT DOWN.
5. You should get a "firewire icon" on HER Mac's screen - this indicates it's booted into target disk mode
6. Now boot YOUR Mac using the system install DVD that came with it. Insert the DVD, press the power-on button, and IMMEDIATELY hold down the "C" key and KEEP HOLDING IT DOWN. You should boot to the installer
7. You will first need to open Disk Utility (which I believe is under the "Tools" menu bar when booted from the install DVD, and re-initialize HER Mac's internal drive
8. Now you can go to the installer, and begin the installation process (as if you were going to do the installation to YOUR OWN Mac). BUT -- at the appropriate moment -- you need to switch the disk to HER disk which should appear in the installer's list of volumes to which you can install to.
9. Let the installer do its thing. When done, you're going to have to power down at the appropriate moment, or "pull the firewire cable" when HER Mac reboots (after the installation is complete)
Now boot HER Mac up -- see what happens. Do you "get a good boot" (and get to the "Welcome to Mac" video?)
If you don't, oh well, at least you tried (see closing comments below).
But if you DO get the "Welcome to Mac" video, IMMEDIATELY create a new administrator account (I suggest you ask her in advance how she wishes that account name/password to be), and then go to Software Update and run the available updates.
When they're all in and installed, see if you can reboot.
If you can, you're home. You made it.
Closing comments:
How much is it going to cost her to "ship" her Mac to you, and how much will it cost to ship it back to her?
Wouldn't it be a lot easier for her to simply spend $29.95 and buy the Snow Leopard install DVD and do it herself?