Nice online tool to identify the manufacturer by looking up the Ethernet MAC address.

http://www.techzoom.net/lookup/check-mac.en

Other alternatives are:

Vistumbler
URL: http://www.techidiots.net/project-pages/vistumbler
Vistumbler is a netstumbler like program for Vista (or later...maybe).

Features
* Find Wireless access points - Uses the Vista command 'netsh wlan show networks mode=bssid' to get wireless information
* GPS Support
* Export/Import access points from txt file
* Export access point GPS locations to a Google Earth KML file
* Open Source ( AutoIt Scripting Language - http://www.autoitscript.com )
* Change column order, column title, and column width in the 'vistumbler_settings.ini' file
* Change search terms in the 'vistumbler_settings.ini' file. This means Vistumbler should be able to work with other languages. Change searchwords to what they are in the another language, Search terms can be found by running 'netsh wlan show networks mode=bssid' in a command prompt

Inssider
URL: http://www.metageek.net/products/inssider
Inssider is a Wi-Fi network scanner for Windows Vista and Windows XP. Although NetStumbler, the most popular Wi-Fi network scanner, is free, it hasn't been actively developed for years. We heard complaints that NetStumbler doesn't with Windows Vista and 64-bit Windows XP, so we decided to build an open-source Wi-Fi network scanner designed for the current generation of Windows operating system.

Features
* Works with internal Wi-Fi radio
* Wi-Fi network information (SSID, MAC, data rate, signal strength, security, etc)
* Graph signal strength over time
* Open source (Apache License, Version 2.0)

Nslookup.exe is a command-line administrative tool for testing and troubleshooting DNS servers (also known as name servers).

To use Nslookup.exe, please note the following: 

• The TCP/IP protocol must be installed on the computer running Nslookup.exe 
• At least one DNS server must be specified when you run the IPCONFIG /ALL command from a command prompt.
• Nslookup will always devolve the name from the current context. If you fail to fully qualify a name query (that is, use trailing dot), the query will be appended to the current context. For example, the current DNS settings are att.com and a query is performed on www.microsoft.com; the first query will go out as www.microsoft.com.att.com because of the query being unqualified. This behavior may be inconsistent with other vendor's versions of Nslookup, and this article is presented to clarify the behavior of Microsoft Windows NT Nslookup.exe 
• If you have implemented the use of the search list in the Domain Suffix Search Order defined on the DNS tab of the Microsoft TCP/IP Properties page, devolution will not occur. The query will be appended to the domain suffixes specified in the list. To avoid using the search list, always use a Fully Qualified Domain Name (that is, add the trailing dot to the name).

Nslookup.exe can be run in two modes: interactive and noninteractive. Noninteractive mode is useful when only a single piece of data needs to be returned. The syntax for noninteractive mode is:

nslookup [-option] [hostname] [server]

For example to check all MX records (email servers) for GSMBLOG.COM domain you have to type this:

nslookup -type=mx gsmblog.com

 and it will return something like this:

Server:  speedtouch.lan
Address:  192.168.0.254

Non-authoritative answer:
gsmblog.com     MX preference = 10, mail exchanger = mail.gsmblog.com

mail.gsmblog.com        internet address = 194.30.175.198

Or to validate the SPF (TXT) record you can use this command:

nslookup -type=txt gsmblog.com

it will return this:

Server:  speedtouch.lan
Address:  192.168.0.254

Non-authoritative answer:
gsmblog.com     text =

        "v=spf1 ip4:194.30.175.0/24 a mx -all"

More details:

http://support.microsoft.com/kb/200525

http://www.windowsnetworking.com/articles_tutorials/Using-NSLOOKUP-DNS-Server-diagnosis.html

To determine which Microsoft IIS (Internet Information Services) is running on your PC you can check following table:

• IIS 1.0, Windows NT 3.51, SP3 or available as a free add-on
• IIS 2.0, Windows NT 4.0
• IIS 3.0, Windows NT 4.0 SP3 (IIS 2.0 is automatically upgraded to IIS 3.0 during the install of SP3)
• IIS 4.0, Windows NT 4.0 Option Pack
• IIS 5.0, Windows 2000
• IIS 5.1, Windows XP Professional, Windows MCE
• IIS 6.0, Windows Server 2003, Windows XP Professional x64 Edition
• IIS 7.0, Windows Server 2008, Windows Vista  

Up to date list is available here