I am trying to install the latest version of Arduino software in Windows 7. I get the error message "Can't write: C:\Probram Files(x86)/Arduino/hardware/tools/avr/bin/avrdude.exe. If I choose to retry, nothing happens. If I choose skip, the install completes, but I cannot upload files to the Uno. I went back to 1.0.6 and get the same message when I try to upload. Also, Arduino says that the comport is already in use.
Sounds like that file is either in use or protected. Rename the C:\Probram Files(x86)/Arduino directory and re-try the install.