In my laptop, I am running Windows 7 - 64 bit. I just formatted the hard disk and installed Mathematica 188.8.131.52.
However, when I start Mathematica, it takes about 2 minutes to initialize the kernel connections. After that, everything runs as it should (with no problems at all).
I noticed that when the network connections are off, the program starts regularly. I think that it tries to get some information from the internet, or to establish some connection to the internet. Any ideas how I can solve this problem?