What not do when you have 10 and 7!

OK, over the summer a task set for me was to restore a Notebook that had been taken off the network to Windows 10 (when on the network it had been Windows 7). The Network IT guys normally flatten a drive completely (so no factory restore) and even with the media available, that did not work (because the hidden restore partition was missing). After contacting the manufacturer's support desk, only to be told "Your laptop is out of warranty," and me politely correcting it to 'Notebook' as stated on their US site, I somehow lost the call but got an email on helpful advice links on restoration. Great! An iso could be downloaded to USB! As the app to download the image could not be done at work due to Admin permissions, I took a works thumb drive home to download the image to. Forgot the works thumb drives available are only 4 Gb in size. So I backed up my 64 Gb Patriot which had 25 Gb of stuff I did not want to lose. I booted into my Windows 10 Insider Pro drive and as it is a bit flakey, decided to backup to my Windows 7 Pro drive (User | Desktop) - "You don't have permission to access this folder. Do you want to make it permanent?" "Yes ..." BIIIIGGGGG MISTEAK (pun/typo error intended!). Download the .iso successfully to the Patriot thumb drive (this is what I hate about Windows, if you want to create an .iso of Windows "it will delete everything on the drive" even though it only needed 16 Gb of space!

So I decide to boot into Windows 7 Pro ... swirling Windows logo then ...

nada - just a black screen and a mouse cursor. Having visited the Microsoft Community pages have discovered that what 10 does is that it overwrites the registry keys in 7 with regards to permissions, as evidenced by another user (who fortunately had backed up his permissions reg keys). Fortunately for me my Zorin Lite 12.4 saved the day by accessing my 7 hard drive so I could then backup all my critical data and downloaded programs purchased recently. What was telling is a new folder had appeared on the system partition of 7 - "Win10Upg" - so now I have FerenOS (based on Linux Mint 19) and a Virtual Hard Disk in Virtual Box housing my Windows 7 Pro so that that naughty Windows 10 will never have access to my 7 again.

Not really sure what your point is?

Not really sure what your point is?

If you have a Windows 7 install on one Drive and Windows 10 on the other, NEVER access the Windows 7 drive from Windows 10 - or you can say goodbye to Windows 7 install.

If you have a Windows 7 install on one Drive and Windows 10 on the other, NEVER access the Windows 7 drive from Windows 10 - or you can say goodbye to Windows 7 install.

I have 2 drives, one with 7 on one with 10 on.. on a daily basis i boot into both, and access the 10 drive via 7, and the 7 drive via windows 10. Never have i had a problem over the past few years.

I have 2 drives, one with 7 on one with 10 on.. on a daily basis i boot into both, and access the 10 drive via 7, and the 7 drive via windows 10. Never have i had a problem over the past few years.

OK, perhaps I should be more specific. Don't access a User file (I should point out that it is the insider version if I haven't already) or the permissions will get taken over by Windows 10. A user on Microsoft community had the same issue with standard Windows 10. I will try and find the link.

I will just throw this in it may help, on the other hand it may confuse

You will probably find this is down to the computer firmware, most machines running W7 use BIOS as the firmware utilizing a Master Boot Record (MBR),

whereas machines running W8/8.1/10 have UEFI impelementing GUID Partition Table (GPT)

I have on old ASUS board originally running Xp, but is now used for W10 Insider Preview, thus being BIOS firmware it uses an MBR.

When W10 preview view was first released I was switching discs between the old machine with BIOS and a relatively new machine with UEFI. and

encountering alsorts of problems. The take-away message for me was, ensure you have reasonabley up to date hardware,

Hi Mikes10,

It's an old rig using mbr. And I found the contents of a locked thread:

"I just spent about 30 hours hacking this problem and here is what I found.

First this was a result of a computer upgrading to windows 10 without asking.

I did the roll back to windows 7 and which then resulted in the Black Screen with a Cursor.

The only response I could get was if you held the Windows Key and U or P

for the handicap feature or dual Monitor setting.. No Logon Screen, No Ctrl-Alt-Del

First I drive Imaged the Hard drive to a second drive so I was free to experiment. I tried just about every suggestion I could find on Google and Microsoft ... None of which worked. It had nothing to do with permissions or drivers.

Safe Mode, command prompt did not work etc, restore to previous did not work(looks like win10 deleted all my old restore points... Thanks MS)

It was the registry that was screwed up and causing the problems.

(I used a second computer and usb HD Caddy to mount my hard drive in a working computer)

Unfortunately the backup of the registry was no good either, windows 10 must have found a way to mess it up as well. I had an older backup of the the registry files which I copied into place at

(X: is drive letter of your Hard Drive your Trying to fix)

X:\windows\system32\config

there should be a backup in

X:\windows\system32\config\regback

(files you need to restore are

default

sam

security

software

system

) I did not test to see which file was the one the problem was in I copied all 5

I can't stress how important it is to make backups of these files, (I used to do this always in XP do to various problems that could happen and even more so back in win98 ) You are almost always forced to reload windows if you can't fix these files."

From page 4 of this thread:

https://answers.microsoft.com/en-us/windows/forum/windows_7-system/windows-7-boots-to-black-screen-with-cursor-before/c3538f76-86a1-462e-8ad7-f319f207a922