Registry keys after restart

Whenever i nstall larger updates, such as ie8 or some other major security update patches that require you to reboot, i often get a black screen after the boot up loading screen & before the logon screen windows logo.

Usually it displays either registry keys, or counting up numbers layed out like below

(498678/578764)

or

(498757/867436) USERS\Regkeysdtable\blah blah\......


Anyone know what this means or why i often get this? Do any other users see this?

Im a bit worried my registry is in tatters or something.

I've seen it once on my computer last month I think. Is your computer running like it was before the update.

yeah its running ok.

(so far)