I don't have Windows 7, but I will share my expierence real fast, which may help you also.
I am a mac user, but I wanted to sync my phone for use on a windows (work) computer. So here is what I know about the sync.
After connecting the phone, you need to go onto the phone's homescreen and pull down the notifications bar (putting your finger on the upper left corner of the touch screen and pull the bar all way to the bottom of the screen). I have HTC sync for the PC (from HTC website) to sync to and I click 'HTC Sync" on the phone's screen. Then I ethier let it update all information (from the computer screen you can cancel the operation) or just stop it (whichever you want to do). Then on the phone under that same pull down notifications bar, click "USB Connected" and it will then ask you to "mount" or "un-mount" the phone's internal hard drive. Click "Mount" and then go onto your computer under "My-Computer" or "Computer" (which ever Windows version you have) and there will be a usb device there that you can go onto like a jump drive or other USB hard drive.
When done, you need to safetly eject the drive (like you do for every jump drive you eject in the lower right corner of the computer). Then check the phone under notifications and check to see if you need to "un-mount" the phone or not. Then unplug and play!
Hopefully this helps, enjoy!