how to dual boot xp & w7 using two "already installed" OS's on system

I am totally new to EasyBCD, so forgive me in advance.

I have two "already installed" OS's residing on two separate disks, one W7 and the other XP. As an after thought I found out about EasyBCD, downloaded and installed it. It doesn't seem to work for me. Every time I select Windows XP in the boot menu, I am getting one error message or another. Having installed EasyBCD on W7, I tried adding a 2nd entry for XP. The boot up menu shows both OS's, XP fails. I tried using the automatic detection settings and each of the available disk Disk partitions on the XP drive. XP just doesn't boot, but W7 works fine.

After doing some reading, I discovered that I should have installed the first OS, then the second OS on the second without disconnecting the first drive. But I didn't. In one of the forums/wiki's, I saw a statement that it was "incredibly difficult" to make it work in the scenario that I find myself in.

However, even though incredibly difficult, are there instructions on how to go about this?

I know, I know, it appears that I might have screwed up, but any instructions would be appreciated.




Knows where his towel is.
Staff member
If your W7 OS is UEFI then you won't be able to boot an MBR XP disk from it.
If it's not,
Boot W7.
delete any XP entry(ies) from the BCD and add a new one, letting EasyBCD auto-configure.
Don't change anything EasyBCD did !
If you think it made a mistake. It didn't.
The "extremely difficult" wiki quote dates from EasyBCD1, where the user had to understand the mechanics of XP boot and manually create and correctly position, various non-BCD XP resources.
All of that is done for you by EasyBCD2, but don't try to second-guess it and "correct" anything.
After you boot XP for the first time from the BCD entry, apply this hack to the XP registry
System Restore Points - Stop XP Dual Boot Delete
otherwise you will lose all your restore points on both systems every time you change your OS choice.


Knows where his towel is.
Staff member
Hi Terry,
I have another challenging situation (for me at least). I have two hard drives, one with W7, the other W8.1. The particular PC they reside in is not UEFI enabled, but uses a traditional BiOS (Dell optiplex 755). The optiplex 755 only allows booting from the drive attached to sata0, thus can not be selected from its native boot menu.
I installed EasyBCD on first drive (Win7), but it does not detect Win8.1 on the 2nd drive.
Is there a way that I can manually add Win8.1 to the bcd record?



Knows where his towel is.
Staff member
You can't boot a later Windows from an earlier bootmgr (invalid dig sig), so normally the advice (on anything but a Dell) would be to change the BIOS HDD boot sequence.
Since you can't do that, your options are
1) physically swap the drive cables between the two HDDs and boot W8.1, then add a W7 entry to 8.1's BCD with EasyBCD.
2) replace the (smaller) W7 bootmgr with a copy of the (larger) W8.1 version and then add an entry to the W7 BCD for 8.1.


Knows where his towel is.
Staff member
Yes. (though I'll be keeping W7 and letting W10 update 8.1. The former being good and the latter rubbish - W7 also the last OS with a decent working WMC. W10 will delete it wherever it finds it)
Thanks so much, Terry.

Yes, I did the update this morning and EasyBCD has enabled the dual boot- thanks again.

I agree with you regarding the rubbish quality of 8.1. Of the several PC's I have, the one in question is the only remaining PC that still has 8.1 on it - keeping it for reference to support others who have it. As far as the other PC's, I have reverted back to W7 (WMC being one of the main reasons). Although I have been using NextPVR recently in place of WMC on most PC's. It's a little buggy in places, but overall more reliable than WMC AND it is being actively supported.