Outlook 2010 cache

I always have this slowness problem when opening my Outlook. So, a bit frustrated, I seek Mr Google for advice, the greatest "know-all" consultant immediate told me the answer.

What I did was to close Outlook, then delete the OST files from hard drive, C:\Users\username\AppData\Local\Microsoft\Outlook. This is for windows 7.

Re-launch Outlook, wow...not only it open fast after the one-time sync to local cache, it cleared away the space used by the old cache, thus, saved me disk space.