Free Network Scanning tool for Windows : Netscan
If you have a LAN at your office or home, the you must probably have used the My Network Places tool in Windows. But it is very slow and lacks in functionality. Thats where the Free and better Network Scanner tool Netscan from Softperfect comes in handy.

Netscan's main merits are that it is a freeware, it doesnot require any installation and it is lite at only 631kb. According to the makers the
Key features are
Pros :
* Pings computers.
* Does not require administrative privileges.
* Detects hardware (MAC) addresses even across routers.
* Detects hidden shared folders (normally invisible on the network) and write accessible shares.
* Detects your internal and external IP addresses.
* Scans for listening TCP ports and SNMP services.
* Retrieves currently logged-on users.
* You can mount and explore network resources.
* Can launch external third party applications.
* Exports results to HTML, XML, CSV and TXT
* Supports Wake-On-LAN and remote shutdown.
* It is absolutely free, requires no installation, and does not contain any adware/spyware/malware.
advanced features like open port detection and hidden folder detection. Also finds if a drive has write access. Free of cost. Light
Cons :
Slow. Unable to stop a scanning process even though an option is provided. Slow response
Conclusion :
Although Netscan is Free it is comparatively slow and tend to forget some of its own features.
Go for it if you are not a power user and just neeeds to scan network.
This one is not for geeks get away if you are one !
Most of us have at least once faced the problem of a PC getting sluggish all in a moment. And we may conclude that it is due to a low memory or a demanding program. The above conclusion is not correct always as I found out the hard way a few days ago.