Windows 10: Win10 Install For Dual Boot Partition Problem

I'm trying to do a clean install of Win10 on my Win7 desktop using Unallocated Space on the HDD. I thought I could have up to 4 Primary partitions, but I get this error when I try to select it. Any ideas?

:)

 

Dual Boot?

I can help here iv had both i used partition magic to split my HDD and i installed vista on one and xp was already on the other only problem is id watch out if i were you for some reason vista does not like to dual boot iv seen this on a couple of my machines and my buddys. so step one have xp installed step 2 find a partitioner of your choice i dont know of any except partition magic and the one included on xp...only thing is i dont think the one on xp will even partition them...then pop in your vista DVD and select the drive of your choice....the only thing i can think of that causes vista to hate dual booting sooo much is that when their are 2 OS's installed xp uses its own prog to list them on boot well vista uses a totally diff boot loader than the previous os's and i think they conflict the problems i hade were the standard missing windows folder missing HAL.dll and the nt one dont remember the name.....that and after your done vista and boot into xp things didnt like to start correctly specially if you scan disk with vista.

 

Dual Boot Win7 & Win10

Here are my steps for dual booting:

• Create a system image - store it on an external drive
  
  
• Disconnect from the Internet and stay disconnected - part of the install asks about connecting
  - do NOT connect just yet.
  
  
• Create the space for the 2nd OS.
  This is tricky - drives initialized as MBR can only have 4 partitions (an extended partition allows for more),
  many OEMs create 4 primary parts and you have to adjust their disk schema.
  
  Post a Disk Management screen shotClose the left and right panes
  The columns should also be stretched to clearly show the values, most important is the Status column
  If you have many drives, you might have to adjust the middle separator and drag the bottom edge of the window down to show the maximum information.
  Then in the View menu, pick Top and change it to disk list - no need to post a pic - just note the initialized format (MBR | GPT) and post the information.
  
• Unless the 2nd OS will be used on a daily basis, keep the space to a minimum.
  Win10 + pgms on my machine takes up about 15 GB.
  I don't use Win10TP as my main OS - that's Win8.1, so data isn't a concern.
  30 - 50 GB is more than sufficient.
  
  
• Once the space is available - take your time here - there are traps with MBR disks.
  If your disk is initialized GPT, no problem - easy! But... MBR - make sure you know what you're doing.
  Just free up enough unallocated space,
  -> do not create a partition and do not format the space.
  
  
• When you're ready to install Win10, use a disc to avoid EFI issues.
  
  1. Boot to the Win10 install disc (see your machine documentation on accessing the Boot Order menu at startup)
     
     +editA
     These steps are probably NOT necessary, it was an afterthought when I installed Win10 the 3rd time as a dual boot to Vista. That is when I noticed the Win10 page file on my Vista boot drive - which caused Vista a bit of a problem (temporary page file created - yada, yada, yada) - I recreated the Win10 page file on it's own partition and then reallocated the Vista page file for good measure.
     
     At the first Win10 install screen, Press Shift+F10
     Then enter these commands in the Console window
     
     ^^ denotes comment, not a command
     Launch Diskpart
     lis vol
     
     ^^ remove the drive letters from all drives
     ^^ it's easier if you disconnect external drives that aren't needed for this exercise.
     
     sel vol #
     remove letter=
     ^^ specify the letter that was shown for that volume in the lis vol command
     ^^ repeat this (select volume, remove letter=) until there are no volumes with letters shown in lis vol
     lis vol
     exit
     close the Command prompt with the X in the upper right hand corner
     
     You should be back in the Win10 install now.-editA
     
     
  2. Answer the questions as if you were doing a clean installation (language, region, etc)
     
     
  3. Choose a custom install
     When it asks you where you want to install, choose the unallocated space
     Let the install complete, the rest should be easy.

+editB
When Win10 boots up, you shouldn't see any other drives - this is good.
Configure the volumes for each OS - I suggest that you keep the two OSes separate, only expose the volumes you need to for each OS. Your Win7 should see everything except the Win10 volumes. Your Win10 should only see volumes you'll use in testing (i.e. what ever you create on the currently new and blank SSD).
If you need data from your existing Win7 install, it's probably better to copy what you need than to expose your good data to Tech Preview code.
-editB

When Win7 boots up, you will see the Win10 drive - remove the letter from that drive. Keep your system separate.

If at any step above you need some help, please ask ... you might have to wait, please wait. The hardest thing to do is wait and the easiest thing to do is "ooops, but I thought you meant...."

I think I remembered all of the steps I took - but... I'm human too *Wink

 

How to go about building a tri-boot system?

i dual boot all the time, and going in to tri boot is easy.

step 1) partition the drive in to 3 partitions ( leaving 1 empty for the linux installer. )
step 2) install windows on the first 2 partitions.
step 3) install linux, and let it auto partition the remaining space. ( i recommend at least 30gb of space for linux, because it will make things a lot easier. )

step 4) enjoy.