How can I share a drive with my network, so that I can access the drive form my mobile (any device) which is connected to the same network (same wireless modem).
I did try it once and when I tried to access the drive from ES File Explorer (Android app) it was asking me user name and password. I did not have any passwords on my system.
OS : Windows 7
Sharing a drive with across a network is easy with windows 7. First, hit WindowsKey + E to open an explorer window. Right-click on the drive you want to share, and Share With > Advanced Sharing
Click the Advanced Sharing button, then name the drive as you see fit. You will also need to assign permissions, which can be done granularly, or you can use the user 'Everyone' and its all access for all.
Click OK or Apply to save your changes and your drive should be available on the network by going to \\Your_PC_Name\Shared_Folder_Name
Keep security in mind if you share this network with other people. If you give all access rights to everyone, then anyone can delete/alter files. However if you give named access to individuals, you may not be able to access the share from a device such as a phone.
A final note, if you end the share name with a dollar sign ($), then the share will be hidden from users casually browsing, and they will only find it by explicitly typing in the name of the share.
Much like the answer provided by Lee, there is one more step that is important for this to work. You will need to go to "Control Panel\Network and Internet\Network and Sharing Center\Advanced sharing settings"
File Sharing you need to go under the "Password protected sharing" section and tick "Turn off password protected sharing" Don't worry other folders you share can still be protected by an account. However without doing this devices like ES File Explorer can't even browse to the folder without some credentials even with it being share with the "Everyone" group.
EDIT: Also check the security tab as well in the general folder settings to ensure the "Everyone" group is also there to read.
