how to remove windows server 2012R2 from dualboot setup?

The correct procedure based on your Disk mgmt screenshot would have been to delete F, boot the server installer to create a new partition there, format and install Server.

You have a separate partition for your data, and all data should be backed up anyway against HD failure. Anything less is reckless. Use an external HD, another internal HD, or a modern cloud method such as Sync, Backup and Store your Files to the Cloud with Skydrive - Windows 7 Help Forums

Why would you delete an OS piecemeal from F when you can correctly delete F in Disk Mgmt instead? It isn't the System partition which is Dual Booting both OS's so it would do so easily.

I have already explained that there is boot code and hidden files which you leave behind if you delete an OS in pieces like that.

If you reinstalled Server to F with the data still on it, how did your data avoid being overwritten? Windows.old folder is not a backup solution more recklessness.

gregrocker said:

The correct procedure based on your Disk mgmt screenshot would have been to delete F, boot the server installer to create a new partition there, format and install Server.

You have a separate partition for your data, and all data should be backed up anyway against HD failure. Anything less is reckless. Use an external HD, another internal HD, or a modern cloud method such as Sync, Backup and Store your Files to the Cloud with Skydrive - Windows 7 Help Forums

Why would you delete an OS piecemeal from F when you can correctly delete F in Disk Mgmt instead? It isn't the System partition which is Dual Booting both OS's so it would do so easily.

I have already explained that there is boot code and hidden files which you leave behind if you delete an OS in pieces like that.

If you reinstalled Server to F with the data still on it, how did your data avoid being overwritten? Windows.old folder is not a backup solution more recklessness.

Yes I installed it with my data in it and it was there after installation no harm to that.

And why would it be..

Also where can I see the boot code left by the piece wise removal?

Tell me the commands to see the boot code left by this piece wise removal.

I have mentioned earlier that used easy bcd to remove the entry for server.

I'm not going to debate Best Practices with someone who doesn't even back up their data.

The correct way to delete an OS is to delete its partition.

The data should always be backed up.

If you pull an OS out by pieces it will leave boot code and may leave hidden files. It is never correct and only a last resort.

If you install an OS over data it will overwrite the data. At best you could hope for a windows.old folder if the partition isn't formatted first, but that is a risky backup method for the lazy.