Prevent programs from loading at startup

Remember back in the good old days of Windows 3.1 when you could open up the Win.ini file in a text editor and remove an item from the RUN= line to disable it from running at startup? With Windows 9x and above, the Win.ini file became less useful because 32-bit programs were set to run at startup from within the Registry instead.

One way to selectively disable programs from loading at startup is to use MSCONFIG (from the Run command) to deselect certain items. Another way to remove them is to edit the Registry directly. Consider the following locations:

HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun

for applications that start up for all users

HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRun

for applications that start up when the current user logs on

Remove the entry for a program by right-clicking it and selecting Delete to prevent it from loading.

source:here