Moving it to my own computer and trying the same gives an other error:
"Error - Access to the path 'entries' is denied."
We have the same issue this morning with this website. I reported it as a bug on the installation manager this #14916. You cannot (currently) have your website installed in a different volume than where the installation manager is.
The solution is to move your site to c:. You cannot choose were to install the manager, it will go into the <program files> volume.
When a site is upgraded to R2 the EPiServer UI directories are removed from the site folder and added via virtual path provider configuration in web.config.
The upgrade is done in a transactional manner so the directories are moved to the Windows temp folder in the first phase of the upgrade, and deleted in the commit phase.
Unfortunately the move step fails when the temp folder resides on a different drive than the site.
To work-around the problem you can move these folders manually to a temporary location before completing the upgrade wizard.
The affected folders are listed on the 2nd page of the upgrade wizard.
Another change that I see is that my own urlRewrite provider isn't necessary anymore.
FriendlyUrlRewriteProviderNoRebase doesn't compile anymore but the ordinary EPiServerFriendlyUrlRewriteProvider does the trick the right way now.
I'm trying my best to do an uppgrade from an EPiServer CMS 5 SP3 to R2. The Installation Manager gives me an error messege.
"Error - Source and destination path must have identical roots. Move will not work across volumes."
My site is on my F: -drive and the manager is on the C: drive.