updated ipad 2 & mini ipad

I have windows 7 64 bit and I just updated my ipad 2 and mini ipad to ver 7.06. I first updated my ipad 2 which went okay. My mini ipad download the update and was extracting but it kept still there for a long time so I updated via directly on the mini ipad and not from my laptop. I then got a message via itunes that the mini ipad could not be backed up. The update was installed anyway.

My question is the following:

I noticed there are two files in the following directory: c:\user\owner\appdata\roaming\apple computer\itunes\ipad software updates. They are the following:

the ipad 2 was done first and then the mini ipad. Why are there two updates in there with two different file sizes. Also can I copy and paste them onto my exterenal hard drive and remove them from my laptop hard drive. Would it cause a problem? thanks