Nope it should work. I suspect you had the xp drive attached when you installed vista>>WIN 7 and they both added files to D:\boot, hence the problem. When you moved it it fixed win 7 but XP may not work.MS-MVP 2010, 2011, 2012 Sysnative.com Team ZigZag

Here's the deal: My dad hates not having free space in his PC, so yesterday he decided to do something about it and he found out that he could compress files in the whole hard drive. His PC has 3 Hard Drives: C (Windows Installation) D (HDD from his past PC) F (Backup) So he compressed D and F, I reallized he was doing this almost when the process was almost over so I let it finish and then I decompressed files I knew they couldn't be compressed. Today in the morning he tried to turn on the pc, but when it tried to boot it showed the message "BOOTMGR IS COMPRESSED" so I tought that the bootmgr form the old pc was still on the D hard drive and it was detected first than the one on C so I changed the boot order, but it didn't change anything. I used the Win repair disc to try to fix the startup, it didn't work. I uncompressed the hard drives from the disk but it showed an error prompt that some files needed Admin Priv to get uncompressed so I had to ingore them and it didn't work. I used bootrec.exe to try to fix it and the following happened: /FixMbr - It ran but did't do anything /FixBoot - Said "File doesn't exist" /RebuildBcd - Identified Win7 install but when trying to add it to BC D said "File doesn't exist" I don't know what else I can try... Any ideas?

When you multi boot a hidden "system" folder is created on the same HD as the oldest OS.What OS'es are involved and where are they located? MS-MVP 2010, 2011, 2012 Sysnative.com Team ZigZag

The D drive has some files from and old WinXP install but I installed a fresh Win Vista in the C hard drive and later I upgraded it to Win7. I just came up with the idea that rewriting the bootmgr should work, so i looked for it and found it in D:\Boot so instead of rewritting it I moved it from there to C:\Boot, then I put C in the top of the boot list (actually second, just behind the DVD drive) and it booted perfectly! Just, I'm not sure if I should do something else, just to be sure.

Nope it should work. I suspect you had the xp drive attached when you installed vista>>WIN 7 and they both added files to D:\boot, hence the problem. When you moved it it fixed win 7 but XP may not work.MS-MVP 2010, 2011, 2012 Sysnative.com Team ZigZag