Where can I find debug.log? Its not in %ProgramFiles%\Bitcoin with the executable.
From the wiki:
https://en.bitcoin.it/wiki/Data_directory Windows
Go to Start -> Run (or press WinKey+R) and run this:
explorer %APPDATA%\Bitcoin
Bitcoin's data folder will open. For most users, this is the following locations:
C:\Documents and Settings\YourUserName\Application data\Bitcoin (XP)
C:\Users\YourUserName\Appdata\Roaming\Bitcoin (Vista and 7)
"AppData" and "Application data" are hidden by default.