I found this in a few different places around the 'net - hopefully it's helpful:
Change the Default Opening Folder in Windows Explorer
By default, Windows Explorer opens showing the My Documents folder. To change the default setting so that all top?level drives and folders are shown, follow these steps:
- Click Start > Programs > Accessories, then right?click Windows Explorer, and click Properties.
- Under Target field, which reads %SystemRoot%\explorer.exe, add to make the line read:
%SystemRoot%\explorer.exe /n, /e, /select, C:\
- Click OK.