Q:

I cant run `start-hbase.cmd` `Error: Could not find or load main class .F` and `ERROR: Could not determine the startup mode`

I cant run start-hbase.cmd. I was able to run start-hbase.cmd yesterday and it worked fine, but now if I run start-hbase.cmd I getError: Could not find or load main class .F and ERROR: Could not determine the startup mode. I restarted my laptop and still not luck. I tried reinstalling from here and not luck. http://apache.claz.org/hbase/1.2.6/hbase-1.2.6-bin.tar.gz
See following console output.
  C:\hbase-1.2.6\bin>start-hbase.cmd
Picked up _JAVA_OPTIONS: -Djava.net.preferIPv4Stack=true\
Error: Could not find or load main class .F
ERROR: Could not determine the startup mode.

A:

So it was an issue with my Java Arguments.
When I removed the system variable _JAVA_OPTIONS which was set to -Djava.net.preferIPv4Stack=true\ the error went away and I was able to start hbase.
What's even more odd is I added the _JAVA_OPTIONS back and restarted my laptop. Ran the start-hbase.cmd again and it was successful. 
If someone could explain this then I will accept that answer. Thanks.

