Microsoft's September security update is likely to cause some disruption in businesses with five critical patches for core Windows operating systems.
All the updates to be released on Patch Tuesday next week are critical, but two will require mandatory restarts.
Both server and desktop management IT groups will be impacted by the updates, according to IT services firm, Lumension.
Four of the critical vulnerabilities affect Windows Vista and three affect Windows Server 2008.
Windows 2000, Windows XP and Windows Server 2003 will also receive updates on Tuesday.
Microsoft has said that it will issue a patch as soon as it is available, but analysts have said an update for IIS 5 and 6 is unlikely to be ready by Tuesday next week.
The fact that four of the updates affect Vista could have implications for the coming Windows 7 operating system because of the significant amount of shared code, said Andrew Clarke, senior VP at Lumension.
"Some of these security bulletins could apply to Windows 7 or Server 2008 R2, but this is not addressed in the information in Microsoft's advance bulletin," he said.
Other commentators have criticised Microsoft for the vagueness of the September advance bulletin that provides little information about what to expect.
Companies with access to the RTM builds should track the bulletins in the future to see if they are updated to apply to Windows 7 and Windows Release 2, said Clarke.