For Windows 7 and Windows 8, when you connect a Nexus 7 tablet by USB, the operating system will make a sound and it will start to install the driver for the tablet.
If after the driver was installed, nothing happens, you don’t see the tablet as a partition, go to settings, click on “Storage”, click on the right corner icon (the three squares) and click on “USB computer connection”.
Click to enable “Media device (MTP). Nexus 7 will now appear as a partition on your computer. You can access the files from it.
The USB debugging option can be enabled or disabled, it doesn’t matter.