Vista - Sort by date? And Folder missing files

Ive got vista x64 and Im tryin to figure out how to sort a folder by the date I DLed the contents. In Xp it was np but I cant seem to get it work in vista. Ive tried Date Received Date Modified Date Taken... everything with Date in the sort type and none of em work they either dont change at all or just end up in abc order. What Im goin for is sorting the contents exactly by date and time of how they ended up in the folder. Any ideas? Also before I forget about it. Ive got a folder on an HDD that wasnt modified when I installed vista I installed vista on a completely new HDD. Now in windows explorer in vista that folder thats on a completely separate drive is missing roughly 100 files completely randomly. Not any specific order I can find to whats missing (date, abc, etc) theyre just not showin up. The file size of the folder doesnt indicate theyve been deleted they just arent showin up.