MBR/BCD Recovery

Xeno Morph · 13 Nov 2012

I have looked at some of the other posts, but I didn't find answers to my specific questions. I have an older pc with Win 7. I bought new hd to have dual boot XP/W7, and I made the mistake of installing XP without first unplugging Win 7 hd.

Now, of course my Win 7 MBR was over written by XP during installation. I was thinking of using "EasyBCD" utility to recover W7 MBR, instead of manually at the dos/cmd promt. My question is, after W7 MBR is recovered, will I be able to boot from either XP hd as well as W7 hd? Do I have to make any changes to the BIOS? The answer to this next question may be obvious, but just want to be sure.

Do I disconnect XP hd during recovery, or leave it connected? Do I have to do anything to the XP hd MBR, or is that over written during the recovery process, (that is, assuming it is to be left connected)? Reinstalling W7 is not an option at the moment, since I have a lot of software that would need to be reinstalled. Finally, would it make a difference if W7 was 64bit OS, or is the process the same as recovering W7 32bit MBR. Don't remember if W7 is 32 or 64bit. Sorry about the barrage of questions. Just trying to cover all the bases. Thanks for any input or insight on this issue.

Baron

Night Hawk · 13 Nov 2012

The first place you will now regret not having gone to first will be the guide for seeing a dual of 7 with the older version. Dual Boot Installation with Windows 7 and XP

The Startup repair tool or command prompt repair commands are the two options available to restore the 7 mbr information since installing XP after 7 as the guide explains will require the rewrite of the 7 mbr entries. That is to be expected.

Once 7 is booting again you can easily add a new boot entry for XP into the 7 BCD store and then decide which version will be left as the default OS as well. If the XP boot files like boot.ini are already present on the 7 host drive XP should load right up. Otherwise you will need to copy the boot files over to the 7 drive and then proceed to edit the boot.ini itself.

Why? The boot.ini file will show "Windows XP rdisk(0)partition(1)" pointing at the second drive. One value would need to be changed to "rdisk(1)partition(1)" to point the ntldr at the second drive in order to see XP start up when selected. I assume however the XP files were already placed on the 7 host as well as the sight of the 7 mbr entries replaced by those for XP.

Read the guide over however since all these points are covered for you. Pay attention to the Option Two portion with XP installed after 7 which explains everything you need to do.

Xeno Morph · 14 Nov 2012

Thank you for the link, very informative.

Night Hawk · 14 Nov 2012

I think you will find the tutorial section here in unbelievable when comparing how well the vast number of guides alone are compared to those found on the web! They are far better illustrated to start with! If you read through and follow the guide there you will up and running both in no time!