Many users of Windows 7 found that after upgrade, they can't find the "Map Network Drive..." option in Windows Explorer. This is because by default it's not shown on Windows 7.
Solution: Open Windows Explorer, press the Alt key. You will see the menu shows again. Under Tools menu, you should find the "Map Network Drive..." option again.
Of course, the net command still work. So, you may create a login script (for domain environment) or a batch to do that. E.g., the command should look like this:
net use j: \\server\sharefolder /persistent:yes
*j: is the drive letter you want
To delete a drive mapping, run the command:
net use j: /delete