Windows 10: Why can't I remove old partitions from previous Windows boot disk?

I have 2 SSDs in my laptop. I fresh installed Windows on what was previously my D drive. My old C drive still has EFI System and Recovery partitions and I can find no way to remove them. I've tried disk management, when I right-click the partition there is only help option, which takes me to general help using the program. I've also tried DISKPART through cmd. When I select the partition and type delete partition override, I get an error saying "the operation is not supported by the object".I should mention the disk is almost full of other data, and I want to keep this. Hence, I didn't format

:)

 

Disk boot failure after removing old Vista partition

Thank you for the reply, muchomurka! As I indicated in my post, I have already tried all the steps you suggested to no avail:

- I cannot choose startup repair since the computer does not boot from the installation media
- I cannot use command prompt since the computer does not boot further than the POST screen
- I have disconnected and tried out all hard drives individually.

Since I had Win 10 up and running a few hours ago, I can say with 100% certainty that none of the hardware is faulty.

The real mystery is, how come the system won't boot from any media without an empty disk containing an old Vista boot sector being on top of the boot priority list? And which steps to take now that I've cleaned this disk and it does not exist anymore?

Would appreciate any ideas and pointers!

 

W7 Hard drive partition issue

to get rid of that 100 meg windows partition that setup creates for you on a new install on a blank hdd:

- press shift+f10 when on the partition management screen in setup <-- this opens a command prompt
- diskpart <-- start the windows command line partition management tool
- list disk <--- list the installed hdds in this computer for the next step
- select disk 0 <- might have to replace 0 with the number of the correct disk
- clean <-- this will erase all data on the disk you selected one step up- dont use the wrong disk!
- create partition primary <- creates a primary partition taking up all space on the drive, adjust the command if necessary
- exit, exit to exit diskpart and the command prompt
- click refresh in partition manager and select your newly created partition and install to that

 

Removing windows XP dual boot

Ok, here's my situation. I had been running XP on my primary partition, and then Vista (mainly as a trial) on another partition. I just recently decided to stick with XP and format the other partition for all storage. I used Disk Management to do the format, but whenever my computer reboots, I still get the dual boot screen. How do I go about removing this dual boot screen? Or at least, how do I set my primary boot to XP if I can't remove it, so I don't always have to hit the arrow key up to "Previous Version of Windows" every time I boot?