I opened our hardrive on the network and half of the folders were missing along with many files.. . help

Have you tried a SEARCH for them as you mey of accidentally moved them ?

Great thought - no this is on the network server. We have 26 folders - one for each letter of the alphabet to correspond to student name. The missing folders are not in recycle or in other folders. Also, many of the remaining folders have files missing. Is the hard drive going bad. I don't know what reindexing is but is that something we need to we? It is a windows 2000 server.

Have you talked to your network admin? Is the server backed up daily? What is the drive configuration on the server?