Last Sunday night/Monday morning, I had to perform a system recovery (from the discs supplied by HP) on my HP Compaq Presario SR5310F 32-bit desktop computer running Windows Vista Home Premium, (on the recommendation of samone at HP) and just backing up my 90+ GB iTunes library took 12 hours (the actual system recovery took only about 2-1/2 hours, the following morning). After the recovery process was complete, I 'restored' the backed-up files by either double-clicking or just opening the first backup file (the one whose file name ends in '.1') and following the prompts, which placed the files into something called the 'System Restore Files' folder. I thought I could just restore my iTunes library by dragging and dropping the music, video and iTunes folder files from this System Restore Files folder back into their original places on my computer, but while the song titles did show up in my iTunes library, whenever I tried to actually play one, an exclamation point would appear beside the song's title and I'd get the error message 'iTunes cannot find the file'; when I clicked on 'Find missing file'--or whatever it's called--the C < Users < [username] < Music folder would open, and it would be completely blank, with only the words 'This folder is empty' appearing in it. (And BTW, before you try to recommend the 'Finding missing content in iTunes' or 'How to find missing music in iTunes' articles to me, I should point out that I did try all of the steps in those articles, but my iTunes library was still completely empty at that point, despite trying those steps; that was why I finally tried 'dragging and dropping all of those files back into the Desktop, Downloads, Documents--yes, some really large download files, not from iTunes, showed up in the Documents folder--and also a couple of downloaded music files--again, not from iTunes--showd up 'loose' [by 'loose', I mean not in one of the folders (e.g., Documents, Downloads etc.) in my [username] subfolder] in my [username] subfolder, after which, I was able to get most of my song and video titles listed in iTunes again, but they just won't PLAY! Also, it appears I'm missing about 5 GB from my iTunes library now, as it's saying that I only have about 85.15 GB worth of files in it, where before I had 90+ GB worth of files in it.)
BTW, I can play the files I moved to Desktop, Downloads, etc. if I right-click on the individual files in these locations and then click on 'Play' or 'Open With', but they just won't play in iTunes.
And one more thing: I stupidly deleted my 2 iTunes podcast file titles after I discovered that these, too, would not play; is there any way I can recover these--and my iTunes library--without performing yet ANOTHER system recovery and starting over 'from scratch'? (But if that's what I'll have to do, I'll do it--or else I'll just give up and start all over again with the new computer I plan to buy over the Labor Day weekend [it'll be a 64-bit Windows 7 computer, I know that much at least], as most of my music was ripped from CDs or else downloaded from places like Bandcamp or Amazon MP3, and these downloads were saved to a series of USB flash drives; I was informed that if worst came to worst, I could redownload my iTunes purchases, but my 2 podcasts will be lost forever, as iTunes doesn't 'keep' those--or words to that effect...)
P.S. The computer I'm using has only a 250 GB hard drive, of which 223 GB were available, I couldn't perform the 'Consolidate' function so I could properly back up my iTunes library, as, what with the accumulated Windows downloads (I got this computer in February 2008) and other programs, I had only a few (< 10) GB free--not enough to consolidate the iTunes library, and second, the computer malfunctioned just prior to my performing the system recovery, so that I could no longer log on in 'normal' mode, only in the various safe modes. A lady at Microsoft told me I could back up my iTunes library by logging on in safe mode with networking (since I could do that, albeit with the error message 'Your account has been loaded with a temporary profile') and pasting my iTunes library to my external hard drive, but when I tried this, I got a message listing my iTunes library as '(empty)' when I clicked on iTunes in 'All Programs', and needless to say, my iTunes library wouldn't even open in any of the safe modes (I don't know whether it was 'just' my computer, or whether the lady didn't know what she was talking about--she does work for Microsoft, after all).