Safe to put the BootMGR files on main drive?

I recently bought a new SSD and I have been planning to clone my original C drive to the SSD. I know that Windows has a SYSTEM partition for housing the BootMGR that is 100 MB big. Is it safe to put the BootMGR on my main C drive so when I clone the C drive to the SSD, the BootMGR will already be on the SSD? I can then set my SSD as an active disk and change the boot priority in BIOS.

Is this safe? Will placing the BootMGR on my main drive cause system instability or stop Windows from booting?

Thanks for reading.

Layback Bear said:

Here is a tutorial by whs that should be helpful to you.

By whs:
Bootmgr - Move to C:\ with EasyBCD

Is it safe though? I mean, there must be a reason that Microsoft created a separate partition to house it.

I have been running my current multi-boot PCs over 5 years and never had a System Reserved partition.
The bootmgr has always been in one of my OSs, and it never caused any problems for me.
If the HD/SSD is pre-partitioned before installing Windows, the System Reserved partition does not get created.

I might create a System Reserved partition and move the bootmgr to it.
I recently transferred my triple boot Test box from a HD to an SSD.
After the transfer I found the alignment was wrong for the first OS partition.
Fixing it moved a lot of data for that partition, something I would prefer to avoid.
If the first partition is a small System Reserved partition it would be a lot easier to fix the alignment if ever needed.

If I upgrade one of my OSs to Win 10 or decide to reinstall the Win 8.1 OS, I'd probably create the System Reserved partition then.
I would create a 350 MB System Reserved partition, that's the size Win 10 creates.

Gandolf said:

Layback Bear said:

Here is a tutorial by whs that should be helpful to you.

By whs:
Bootmgr - Move to C:\ with EasyBCD

Is it safe though? I mean, there must be a reason that Microsoft created a separate partition to house it.

Actually, MS will NOT create a separate partition if the Win7/8 new install is a second (or more) bootable Windows being added to an existing environment that already contains an "active" partition (which can either be a relatively modern existing "system reserved" partition, or maybe an old WinXP system partition where both Boot Manager and Windows were placed into the same single partition and no separate "system reserved" ever existed) on a harddrive.

In other words, Boot Manager would normally be placed into the first "active" partition found, which normally would be on the harddrive #1 in the BIOS boot device sequence. Many users have BIOS boot sequence to include USB drives and/or CD/DVD drives in front of the first hard drive, to allow recognized automatic booting by the BIOS through alternate devices if you insert such bootable media into those devices. But there is inevitably a first #1 harddrive, and that's where the "active" partition containing Boot Manager should be.

Note that on occasion and dependingon hardware upgrade history stories, there might be additional harddrives in the environment and they might also contain residual "active" partitions (from yesteryear use). This isn't harmful or fatal, but it's a very bad idea and is not really recommended simply to avoid any confusion or possibility of malfunction. For example, if you have a new empty harddrive as #1 but you have an existing older secondary hard drive also present and it happens to still have an old "active" partition, then that old "active partition on the later drive will be used to install the new Boot Manager. Not recommended, especially if you want the first harddrive to have it.

There really should only be one "active" partition on your harddrives, and that partition should be on the very first #1 harddrive in your BIOS boot sequence. Theoretically, if there is no "active" partition on that #1 harddrive the BIOS will continue on to #2 harddrive listed in the boot sequence, still looking to find an "active" partition. But this again is really not recommended. Just have one "active" partition, and have it on the #1 harddrive in the boot sequence.

Anyway, only if the Windows installer does not see an "active" partition on the #1 harddrive in the BIOS boot sequence list (e.g. on a brand new empty hard drive set to be #1 in the BIOS) will a new 100MB "system reserved" now be created and Boot Manager installed into it. But if an "active" partition already exists, Boot Manager in it will be updated (to the latest version from the Windows being installed) and the existing boot manager menu will be updated to add the new Windows OS being installed (into a separate new system partition also created for that purpose), which will also be set to be the new default bootable OS on that menu.

There really is nothing "safe" or "unsafe" about Boot Manager being in its own small "system reserved" partition, or being in some other pre-existing "active" partition when the new Windows install is being performed. Either method works perfectly. What is significant is that it must reside in the "active" partition of the harddrive which really should be #1 harddrive in the BIOS boot sequence.

Alright thanks! This solved the question for me.

AddRAM said:

If you don`t copy over the SR partition too, windows will not boot on the ssd.

Just to clarify...

If the existing spinner 2-partition setup (100MB system reserved "active" with Boot Manager in it, plus non-bootable Windows system C-partition) are both copied to SSD (thus retaining the small 100MB "system reserved" "active" partition where Boot Manager currently lives, along with the second C-partition for Windows), that's fine. Same on the SSD as on the spinner currently.

And obviously just copying just the Windows C-partition alone from the current setup, and not also copying the "active" Boot Manager SR partition, well this is clearly incorrect since there won't be an "active" partition with Boot Manager in it on the SSD for the BIOS to boot to.

But if he first uses EasyBCD on the spinner to relocate Boot Manager into the existing Windows C-partition (thus making it the new "active" partition), then he only needs to copy the newly "active" C-partition (with Boot Manager now in it) over to the SSD, and it will now boot just fine from the SSD since there will be an "active" partition on the SSD with Boot Manager in it (that also happens to be where the Windows system also lives). Standard single partition setup with no small 100MB "system reserved", but instead where the single large C-partition for Windows also contains Boot Manager, and is also marked "active", doing all-in-one service.

I put the BootMGR on my C drive and transferred the C drive to my new SSD. Everything worked out perfectly, thanks guys!

Gandolf said:

Layback Bear said:

Here is a tutorial by whs that should be helpful to you.

By whs:
Bootmgr - Move to C:\ with EasyBCD

Is it safe though? I mean, there must be a reason that Microsoft created a separate partition to house it.

There is a reason, actually. It's to support BitLocker full-disk encryption that's part of Windows. When it's active the normal system partition is encrypted, hence unreadable, so nothing can boot from it. That problem is solved with the"system reserved" partition, which is always left unencryptedl and holds the bootloader. It boots from there, initializes the encryption system and then decrypts and reads the rest of the system.
Even if BitLocker is not used, Windows will create, by default, that annoying partition. There it boot from there and just transfer control to the normal system.

By just copying bootmgr will not suffice for a sucesfull boot. You need to copy the whole contents of the system-reserved to the main drive. You also need to make the drive bootable with the Windows 6.x MBR code, that can be done with the "bootsect" utility included in the Windows installation disk.
I've never tried doing that but my supposition is that those things will make a partition bootable and Windows will start from there.