Can I install snow leopard on an external hard drive so I can run quicken 2006, and put snow leopard on my imac harddrive

Question

Can I install snow leopard on an external hard drive in order to run my quicken 2006, and install lion on the hard drive of my imac?

Answer 1

You don't need to erase the drive and repartition from scratch. You may be able to add a second partition on the fly. The caveat here is that once you do that you cannot create a Windows partition using Boot Camp. Of course if you have no plans for Boot Camp then it isn't relevant.
To create a second partition on your existing startup volume:
To resize the drive do the following:
1. Open Disk Utility and select the drive entry (mfgr.'s ID and size) from the left side list.
2. Click on the Partition tab in the DU main window. You should see the graphical sizing window showing the existing partitions. A portion may appear as a blue rectangle representing the used space on a partition.
3. In the lower right corner of the sizing rectangle for each partition is a resizing gadget. Select it with the mouse and move the bottom of the rectangle upwards until you have reduced the existing partition enough to create the desired new volume's size. The space below the resized partition will appear gray. Click on the Apply button and wait until the process has completed.  (Note: You can only make a partition smaller in order to create new free space.)
4. Click on the [+] button below the sizing window to add a new partition in the gray space you freed up. Give the new volume a name, if you wish, then click on the Apply button. Wait until the process has completed.
You should now have a new volume on the drive.
It would be wise to have a backup of your current system as resizing is not necessarily free of risk for data loss.  Your drive must have sufficient contiguous free space for this process to work.
Now, you cannot add a new partition that exceeds the amount of contiguous free space at the end of the drive. Disk Utility will fail to add the partition if it cannot find sufficient contiguous free space. If that's the case then you will need to follow your state outline - backup, boot from clone, erase internal, repartition internal, restore backup to one of the partitions (or both in your case.)