Windows 10: Transferring files from Local disk C to D

i wanted to transfer some of my files from local disk C to D so because my local disk C is filling up, plz help

:)

 

Is it safe to transfer fies from local disk C to local disk D?

I wanted to transfer files from local disk C to local disk D to free up space on my local disk C. So is it safe to send files from one drive to another and will my PC work properly if I do this?

 

Will my files on Local Disk (D get deleted if i reinstall Windows 10

Suggest you back up REALLY CRITICAL files to cloud as well, just in case things go pearshaped.

 

Need Help Files Transfer

I have a computer running Windows XP Home Edition. That computer has two internal HDDs:

The 1st HDD is C:\ that running Windows. And it has 20GB total of capacity.
The 2nd HDD is D:\ that is empty. And it has 90GB total of capacity.

The C:\ drive is almost run out of space (full). Is there a way I can transfer everything in the C:\ drive to the D:\ drive and begin to use the D:\ drive from there on as primary drive?
Can the Windows Files Transfer feature in XP transfer everything I have in C:\ to D:\? If it cannot, then which way can I use to perform the above step?

Thank you.