What will happen?

Didn't know whether to ask here or in the setup thread. I have Windows 7 & 8 as a dual boot on the same hard drive. I need to re-install Windows 7. I assume Windows 8 has control of the MBR, so what will happen to Windows 8, will 7 override the MBR and if so how do I get 8 back again?
Windows 7 just crashed, screen went blank and now it's a nightmare to use.

\Windows\Minidump

You can copy the files in there to any other folder then zip them. Attach the zip here and we can see what is going wrong.

Use safe mode + networking if needed.

If you just reinstall 7, you'll likely end up in the same place anyhow eventually, from doing the things you normally do (which caused the issue in the first place.)

In the past, when I looked at this, the Windows 7 installation rewrites the boot store and in so doing removes the graphical Windows boot selection screen. However, it does keep the option to boot to either Windows 7 or Windows 8. What you could do is export the boot store prior to reinstalling Windows 7, then once done, import the store. To do this use:

Bcdedit /export {path to somewhere safe}{name of file} For example - Bcdedit /export C:\BootStore
Bcdedit /import C:\Bootstore