If you use a hacked serial, it is my understanding that you will need to enter a valid serial after doing this update so be careful, but i cant confirm this. Here http://support.microsoft.com/default.aspx?kbid=842242 this is microsoft's complete list of programs that SP2 cause's "GLITCH's" in. For the developer crew out there here's a few i needed to know so you might to as well. Visual Studio .NET blocked out by SP2 by default to Remote Debugging SQL 2000a blocked out by SP2 by default to Remote Debugging CUTEFTP Goofy trying to ftp in via port 21 Symantec Corp. AntiVirus 9.0 Updating virus deff. blocked out by default ColdFusion MX Server 6 F'ed up remoting in to a webserver Then "programs that may behave differently" http://support.microsoft.com/default.aspx?kbid=884130 Photoshop Elements Nero 6 Ultra Nero Burning Rom AOL (no suprise there) MSN (no suprise again) ICQ Pro Quicken 2003/Deluxe 2001 Kazaa Mcaffe Parental Control Macafee Internet security suite 2004 Mcaffe VirusScan Excel Office Office Access 2002 Office XP Professional Excel 10.0 SP2 Office XP SP2 - PowerPoint Outlook 2000 Outlook 2002 Outlook Web Access SQL 2000a 2000a SP3 Visual Basic Visual C++ (16-bit) Visual Studio 7 Visual Studio 97 Visual Studio .NET Enterprise 2003 Visual Studio 98 Norton Antivirus 2003 Norton Systemworks 2003c Norton Systemworks 2003 Professional Edition 2003c Norton Systemworks 2004 PCAnywhere 11 Smantec Antivirus Corporate Edition Yahoo Yahoo instant Messenger Yahoo Messenger Unreal II Unreal Tourn 2003 Warcraft III StarCraft DivxPlayer NFS hot pursuit NBA LIVE 2000 Age of Empires II: Age of Kings Tom Clancy's Rainbow Six 3: Raven Shield Tribes 2 (every play that? if not go get it fun game bargin now at 10 bucks) Ok sorry about that... i only pulled out the programs i thought might be realitive. Now for the list microsoft has said the SP2 has fixed. http://support.microsoft.com/default.aspx?...kb;EN-US;811113 there's a ton here so im only gonna pull the most relivant top 5. 1) Removable storage recognizes the tape drive, but it does not recognize any media in the drive 2) 100 percent CPU usage may occur under some battery conditions 3) Hibernation problem on computers with 1 GB of RAM 4) The "ipconfig" command does not return connection-specific DNS suffixes for Windows XP 5) Cannot Disable the Registry Repair and Recovery Feature in Windows XP SP1 6) You Do Not Receive a Message That Was Sent by Using the net send Command 7) Computer Stops Responding (Hangs) When It Writes Encrypted Data to an NTFS Partition 8) MS03-026: Buffer Overrun in RPC May Allow Code Execution 9) MS03-039: A buffer overrun in RPCSS could allow an attacker to run malicious programs 10) Your Windows XP-based computer does not resume from standby when you move your USB mouse or press a key on your USB keyboard Cliffs, make sure you know what your doing or what complications may arise when doing your update to SP2. So of the security fixes that it does cover is pretty conclusive but never the less, weigh your pros and con's before upgrading.