zaujemcom sa mozno bude hodit clanok dotykajuci sa tejto temy od osoby povolanej, Marka Russinovicha:

Registry Junk: A Windows Fact of Life

v skratke: sam priznava, ze po aplikaciach v registroch ostavaju "smeti", ktore vsak odinstalatory z principu nemozu riesit

na druhej strane vsak co sa tyka dopadu na vykon:

Hi Mark, do you really think that Registry junk left by uninstalled programs could severely slow down the computer? I would like to 'hear' your opinion.

No, even if the registry was massively bloated there would be little impact on the performance of anything other than exhaustive searches.

On Win2K Terminal Server systems, however, there is a limit on the total amount of Registry data that can be loaded and so large profile hives can limit the number of users that can be logged on simultaneously.

I haven't and never will implement a Registry cleaner since it's of little practical use on anything other than Win2K terminal servers and developing one that's both safe and effective requires a huge amount of application-specific knowledge.