Ok, this may not be a sharepoint post, but...
If you are like me, you have "Virtual Clone Drive" installed, allowing you to mount ISO files as virtual CDs (other virutal CD software is available).
If you are like me, you do not have a physical CD drive in your laptop (having pulled it out and put a second SSD in instead).
If you are like me, you are running office 2010.
If you are like me, you always install whatever Windows Update tells you to install.
So...if you are like me, then you have been unable to install service pack 1 of Office 2010, failing (of all things) on installing a sharepoint client component.
The solution turns out to be simple - disable the virtual CD drive and then do the update. Some recommendations from Microsoft also suggests to put a DVD or CD in your physical CD drive while patching. Seems to be a bug in SP1.
Lucky for us sharepoint people that the SharePoint SP1 doesnt have all these annoying installation bugs. Oh, wait...