On Windows Vista and every subsequent version of Windows, if I search for a file and include the entire C:\ drive, I might very well have time to make tea or a sandwich while the search results come in. On Windows XP, using the search dialog with the animated dog, I can search the entire C:\ drive and expect it to be done in a minute or two, if not in seconds.
It can’t just be nostalgia; I can replicate these results on period-accurate hardware today. What changed with Vista to make file searching so much slower, even with indexing enabled?
Yes, but no.
The NTFS file system does maintain an index, and software like Everything Search or WizTree can use it to produce almost instantaneous results (probably faster than back in the XP days, even with larger discs).
The problem is that Windows Search stopped using the damn index for some reason (probably to provide sponsored web results and whatnot instead of whatever you were looking for).