Microsoft Exchange  

Microsoft.com: - Official Microsoft website for Exchange Server

OutlookExchange - With regular articles on Exchange and Outlook from Exchange administrators and consultants working on Exchange projects supporting Exchange and Outlook Systems

Exchange Server Newsgroups - TechNet Community for Exchange Server

ExchangeD2D.com - Funded by Microsoft, this site has over 20,000 pages of Exchange content including Admin tips, code samples, mentored discussions, links to 8,300 Microsoft resources, and more.

SlipStick - Utilities, how to's, code samples, discussions, chats, and other resources and other solutions for Microsoft Outlook and Microsoft Exchange

SearchExchange.com - SearchExchange.com, the source for news and tips on Microsoft Exchange and Outlook administration

Exchange Blogs  

You Had Me at EHLO - This is an official team blog site of the Microsoft Exchange Team. Bloggers range from Exchange developers all the way to Exchange support engineers (and everything in between!)

MS Exchange Blog - Regularly updated blog for Exchange news, links and tips

jkOnTheRun - jkOnTheRun is a mobile technology blog that discusses all facets of mobile tech and the integration of same into the lifestyle. James Kendrick writes a lot of original articles that cover a wide range of topics from Tablet PCs to using a hosted Exchange Server.

Learn Exchange in Spanish - Learn to administer your Exchange email server in Spanish. In this Blog we help the Spanish Exchange community with articles, how-to's, news, etc
 

Windows 2000, 2003, XP & .NET  

WindowsNetworking.com - Features a wealth of tutorials on various Windows networking related topics such as setting up Windows NT/XP/2000/2003 networks, troubleshooting, connectivity and more. Also includes a comprehensive archive of reviewed networking software.

ServerFiles.com - ServerFiles.com is THE software directory for network administrators and IT professionals that are looking for networking & server software for Windows 2000/NT & .NET. It's significantly different from other download/software sites in that it does not focus on single user software.

NTfaxFAQ.com - A comprehensive and unbiased listing of Fax server software and gateways for Windows NT. Contains detailed information regarding latest fax software for servers.

Is-It-True.org - Tips and tricks for Windows NT / Windows 2000 admins and users including registry hacks, security tips, book recommendations. Hacking oriented data is presented to support NT / W2K admin's penetration testing.

MicrosoftSearchEngine.com - A search engine that focuses on Microsoft server and .NET technology!Includes links to every web page that has Microsoft Server or .NET information. An easy to navigate site designed for the senior Microsoft administrators, developers and decision makers.

dotNETD2D.com - Includes .NET code tips, complete list of .NET developer products, most every .NET service and training company, links to all .NET web sites and communities, and many discussion forums. 

NTCompatible.com - The Windows NT 4.0/2000/XP compatiblity site with news, compatibility lists, FAQs, and support forums.

WinXPWorld.com - Windows XP news, downloads, message boards, white papers, tips and more...

NTutility.com - Improve the efficiency and security of your networks with these applications designed for Windows 2000, Windows NT and Windows XP.

NetServerWorld - .NET Server World. The best place for news, information, tips and tricks about Microsoft's flagship operating system, Windows .NET Server .

Wown.com - J. Helmig's World of Windows Networking, with hundreds of tutorials and articles on Windows NT, 2000, XP and .NET.

ADSSupport.net - The best source for dedicated, free, Active Directory support, information and advice, offering forums, articles, advice and much much more.

Only4Gurus - Delivers information and documentation which will help coders and IT professionals to get the most out of Microsoft products.

SearchWin2000.com - The Web's best Windows 2000-specific information resource for enterprise IT professionals.

Security  

WindowSecurity.com - Windows security site which provides Windows security news, articles, tutorials, software listings and reviews for information security professionals covering topics such as firewalls, viruses, intrusion detection and other security topics.

Firewall.cx - Contains information on basic/advanced networking concepts, Protocols (IP, DNS, FTP, ICMP etc.), Routing protocols, Ethernet, Routers, Firewalls, DMZ, Security, Subnetting, Supernetting, special sections with networking software, documents and projects for you to download from.

GFISecurityLabs - GFISecurityLabs is the in-house security research division of GFI. It has developed several free security services including EmailSecurityTest & EventLogScan and features security news & whitepapers.

Wilders.org - The ultimate security website. Reviews, (free) tools and services, and more, as well as free support

McAfee Security - Virus Information Library - Detailed information on viruses, with updates on the latest threats, how to remove them and other virus related info.

Dutch Security Information Network - An international Dutch view upon the networking and security world. DSInet.org provides its visitors with information, files, tools, news items, columns, opinions and an editorial view upon the genre in general. A fresh start.

SecurityD2D.com - Funded by Microsoft, this site has Microsoft centric Security content including server admin tips, mentored security discussions, links to numerous Microsoft resources, and more.

Computerworld's Security Knowledge Center - Provides breaking news articles, features, analysis and commentary on issues of interest to IT professionals. Among the topics included are corporate network security, cybercrime, firewalls, privacy, security holes, viruses and worms.

Security Forums - Security portal and forums covering operating system and network security through to troubleshooting and vulnerabilities.

eBCVG.com - Security portal and forums covering operating system and network security through to troubleshooting and vulnerabilities.

AuditMyPC - Free online firewall testing UDP and TCP.

GovernmentSecurity.org - Computer and network security articles and hacking prevention resources for the government.

Certification  

MC MCSE - One of the oldest and most popular certification websites providing free MCSE/MCSA, A+, Network+, i-Net+, CIW and Cisco certification practice tests, study guides, forums and many other resources.

MCSEguide.com - Free Sample Tests, Study Guides, Book Reviews, Forums for MCSE, Windows 2000, Novell, Checkpoint,A+/N+, Lotus, Linux and Oracle. Sign up for our FREE Windows 2000, CCNA and Network+ question of the day E-mails.

Leuthard.ch - Checkpoint MCSE contains free study resources for the MCSE exams and some others.

2000Trainers.com - The free online learning site for system administrators. Free tutorials, practice exams, courses, articles, and discussion forums relating to SQL Server, Exchange Server, and Windows 2000.

2000Tutor.com - Technology Information for the New Millennium - Contains free Windows 2000 Resources, Practice Exams, Book Reviews and the Internet's Most Popular Certification Discussion Board.

MCSE Directory - The directory of the best free MCSE resources on the web - study guides, tests and a whole lot more.

Sasasite.com - Certification Community (used to be go.to/newcheckpoint). Originally created by Thomas Leuthard. Updated by Sasa. Kept alive by you.

Petri.co.il - MCSEworld by Daniel Petri has become one of the world's leading certification resource sites, with thousands of questions, articles, tips and exams for the Microsoft MCSE certification program. You cannot afford not to visit this site if you plan to become a Certified Microsoft Professional.

HarCon.NET - Devoted to all hard working students seeking MCSA / MCSE / CCSA / CCSE certifications, IT Staff or Security Engineers and it focuses on two main subjects, Microsoft OS and Network Security.

ISA Server  

ISAserver.org - With Microsoft ISA Server Firewall related FAQ's, add-on software listings, tutorials, tips, how to's, books, message boards, discussion lists and more about the new Microsoft ISA server 2000

Microsoft ISA Server - ISA Server 2000 provides secure, fast, and manageable Internet connectivity. ISA Server integrates an extensible, multilayer enterprise firewall and a scalable high-performance Web cache.

Windows2000.About.com - Probably the most comprehensive site on the Internet for Windows 2000 and Windows NT information, resources, software, reviews, news and support. They recently launched an 'ISA Server' section with links to hundreds of ISA Server tutorials, articles etc...

LABmice.net - The definitive online resource for IT Professionals who deploy, manage, and support Microsoft Windows 2000 products and services. They recently launched a section dedicated to ISA Server.

MSisafaq.de - Msisafaq.de is a German ISA Server site with step-by-step tutorials and frequently asked questions, all written in German. Main focus is on needs of German small and medium infrastructure.

Toolzz.com - A variety of helpful ISA server tools and utilities available for download as well as links to other resources including security guides.

ISATools.org - One of the most comprehensive public ISA Server toolbox on the net. Most tools are written by Jim Harrison, but some are offerings from the ISA user base.

General IT  

Techworld.com - The computing and networking knowledge centre.

TechTutorials.com - TechTutorials provides free computer reference information including a searchable directory of free tutorials, white papers, tips & tricks, FAQs, HOWTOs and other sources of free technical information that cover a wide range of computing and technology topics.

NetAdminTools.com - Tools, tips, and resources for network administrators.

CompInfo - One-Stop reference resource for corporate IT, computers and communications.

5StarSupport.com - Receive free technical assistance in real time or via the support forums. Also includes a wealth of tutorials, tips, tricks and FAQs that address most common computer issues.

SearchNetworking.com - Networking news, tips and advice for enterprise IT professionals

Spamfo - brings together topical news, product reviews and useful links relating to the world of Internet spam.

Free Online Security Tests  

Email Security Testing Zone - Test whether your email system is vulnerable to email viruses and attacks! The zone allows visitors to freely discover instantly if their system is secure against current and future email threats, such as emails containing infected attachments, emails with malformed MIME headers, HTML mails with embedded scripts and much more!

Event Log Scanner - Check for high security events happening on your machine, such as users logging on to your machine, accesses to important files on your machine, failed logon attempts, security policy changes to your machine, and more! Use EventLogScan to check that your system is truly secure with our free online intrusion detection solution!