Build-your-own screensaver freeware?

Does anybody have any recommendations for a software package that allows a user to put together a series of images into a corporate screensaver? The package needs to be compatible with Win 2000 and Win XP and would preferably be freeware or shareware. There’s lots of stuff out there, but I’m not sure how to identify a reputable source that is certain not to contain any adware or spyware? The screensaver doesn’t have to be terribly sophisticated but some nice dissolves between images or something like that would be nice.

It would be a definite advantage if the slides (or the entire screensaver) could be easily updated across a network environment just by copying down a few files through a login script or some similar mechanism.

Freeware. They ask for an email address, but you can go with a bogus one if you prefer. Select your images, customize the image size, build the save, and it creates a standard .scr file in your /windows/system32 directory. You can use whatever means you prefer to push it over the network.

irfanview also does a good job creating screensavers.