I've spent several days x many hours per day searching online to find the information I'm looking for, but am not having any luck. I have an iMac 24" 9,1 (2009) running 10.6.8 which recently developed some problems -- by all the evidence so far, caused by airflow blockages. It's been thoroughly cleaned (carefully taken apart and put back together) and not acting like it was pre-cleaning, but the trouble experienced (a kernel panic, a number of abrupt shutdowns) appears to have resulted in some file corruption which needs to be further diagnosed, repaired, and may even require either a reinstall or a wipe and then reinstall. For instance, my Mail program crashes very early after starting it, with the error log showing the following message every time, although the thread number varies: Exception Type: EXC_BAD_ACCESS (SIGBUS) Exception Codes: KERN_PROTECTION_FAILURE at 0x0000000124a89ff8 Crashed Thread: 13 Dispatch queue: com.apple.root.default-priority I mention file corruption in the preferences or permission, based on reading I've done. Seems to me that mail plist file corruption very often requires reinstall...is tricky to fix effectively otherwise. Also, there's stuff showing up in Console besides for Mail that points to likely preference / permission corruption. And Font validation showed a list; duplicates, errors, problems..I'm befuddled regarding how to fix anything but duplicates. I understand that it COULD be hardware. I haven't run full diagnostics, repairs, etc., but am going to do so immediately after I ensure I have proper backups. I DO have a couple of layers of backups - particular files on their own and through Time Machine. Based on the reading I've done, I'm not comfortable doing much more in the way of tests, repairs, etc. until I've got another kind of backup, because what I've got is either incomplete (certain files on their own) or is solely dependent upon the Time Machine. The TM backups cause me particular concern due to the space allocated for it and realizing that the problems with my machine were happening for long enough before the clean out that the files are suspect. (TM or cloning isn't recommended when there are system problems...but alternatives aren't listed either.) I want to do one more backup -- one that ensures I can get critical files WITHOUT restoring corrupted files. So I can pick and choose, in other words. To avoid introducing file corruption, I'm willing to do things like setup the Mail program all over again BUT I must have the Messages. I'd LIKE to have my folder structures and I'd LIKE to retain my Rules (filters). Does anyone have any advice on HOW to make a backup so that I can pick and choose specific files, preferences, and permissions to restore or avoid IF I do need to totally wipe the disk and start over, or if it does turn out to be hardware. In other words, one that enables me to ensure I don't lose data/files but avoids reintroducing corruption. Please take it easy on me, if you would. I've been migrating away from Windows towers and spent my first couple of Mac years with literally ZERO trouble until the past couple of months - an entirely unfamiliar computer experience - and now see that I was NOT being realistic nor educating myself in advance of the inevitable issues that ARE going to arise when machines age. I'm trying to avoid spending funds on backup software right now because we have TWO iMacs having problems at the same time and have spent and will spend money on parts (new hard drive, new RAM, new sensors - and new front glass [mishap in repair] in the other one).