Not so fast. Windows XP is now a fairly stable, and increasingly secure OS according to Michael Desmond. He points out the following five reasons to take pause and delay upgrading to Vista:

• Pay that piper: Vista is an operating system. It’s the stuff your applications run on. But it’ll cost $100 or more to make the switch. Unless you’re buying a new PC and starting from scratch, you may be better off saving the money for something else.
• Where’s my antivirus?: For all the hype about security in Windows Vista, users may be disappointed to learn that antivirus software will not be part of the package. There’s every indication that an online subscription service–possibly under the OneCare rubric–will offer antivirus protection to Vista users down the road. But for the time being, you’ll need to turn to third-party companies like Symantec, McAfee, Grisoft, and others for virus protection.
• Watch that hourglass: Vista is a power hog. Unless you have a top-end PC with high-end graphics hardware, for instance, you won’t see one of the coolest parts of the new OS–the Aero Glass interface. Microsoft did the smart thing by offering Aero Basic and Windows Classic looks as well, which will let older and slower PCs run Vista. It just won’t look as pretty.
• Curse the learning curve: Microsoft has already ditched some aggressive ideas–such as the whole “virtual folders” thing–because the concepts proved too confusing for users. Even so, you’ll find that the new Windows changes a lot of old tricks, and not always for the better. Heck, it took me almost five minutes to find the Run command, which used to show up right in the Start menu. And many users may struggle with the new power scheme, which defaults to putting the PC into hibernation rather than shutting down. I know it frustrated me the first time I wanted to power down the system to swap out a disk drive.
• Meet the old boss, same as the new boss: Microsoft has added lots of new stuff to Vista, but some features are just warmed-over fare. Windows Mail is nothing more than a rebranded Outlook Express, and Windows Defender is simply an updated version of Microsoft AntiSpyware.