I am new to OSX and even newer to Outlook 2011. From Outlook for Windows off my old machine, I had 4 archive PST files (2008-2011...one for each year) and my main PST file (basically mail for 2012). Each is large - (7 gigs or so) and I used to keep the archive PST files on an external hard drive with the files tethered to Outlook but generally left alone unless needed. Apparently, this isn't possible with Outlook 2011 for Mac because it doesn't use PST files. So...cutting to the chase, I decided to import all of my PST files on to my new Mac hard drive...and then I was going to try to migrate the archives to gmail accounts via IMAP. Anyway, to make a long story short...the IMAP move isn't working and then Outlook tells me my data file is corrupted and it needs to fix it. It's fixing it alright...I have 155 GB's used (of 250 gb) on my new hard drive with NOTHING on it except Microsoft Office. I think I will need to start over. So, how do I start over? How do I wipe my hard drive and reinstall all programs which came with the machine? I do not have an external CD/DVD. Can this all be done with the system file partition (I assume there is one). What are my options?