Hi,
You have a space in your directory name. There is a bug in DP8.1 that did not take this space into account, and your install will fail. I faced this issue myself.
You can do any of the following steps:
1) Reinstall 7.0 on a directory path with no spaces, then upgrade to DP8.1. You'll have to make sure your DCBF path is still valid.
2) Upgrade to DP 8.0, then upgrade to DP8.1.
3) Upgrade to DP 9.0.