OS Partition Expansion

Andrew,

Do what NavyLCdr said before anything else.

I know nothing about the effects of BitLocker on partitioning work.

By the way, you cut off the right-hand side of the Disk mgmt diagram.
These columns cannot be seen: Capacity, Free space {and, partially, Status}.
I'd like to see it all if you have any further questions [after you have completed the EFI partition rebuild suggested by NavyLtCdr]. But you might not have any.

You have already given the salient facts anyway

andrew124C41 said:

... I used Sysprep to create two partitions, C for the OS and D for data.
Anyway, the present problem is that I only allocated about 70 GB to the OS and now it is full. I can't add any other programs.
I have plenty of room on the D partition.

You could use Disk mgmt to shrink D:\ and then expand C:\ into the free space created.
But many jobs like this are more easily done with a third-party tool such as MiniToolPartitionWizard, MiniTool Partition Wizard User Manual / Online manual. Disk mgmt cannot, of itself, 'align partitions'.
In this case, you will do three jobs in MTPW: shrink D:\, enlarge C:\, align partitions.

- I know that the tool GParted can also check and align partitions but I have not systematically reviewed all partition managers for this capability.
- I used to know how to do the calculations necessary to get Disk mgmt to respect partition alignment but it was a pain in the neck compared to just letting MTPW do the work - see SSD Alignment - SevenForums & Fix SSD misalignment - SevenForums.

I would normally suggest that enlarging C:\ to 100GB is ample for C:\ unless you install games as they can take up an awful lot of space.
If you do not know where all your space has been used up then use Treesize free, How to interpret TreeSize results or an equivalent.

All the best,
Denis

Hello @andrew124C41,

Try3 said:

By the way, you cut off the right-hand side of the Disk mgmt diagram.

As a Windows Tool, Disk Management is the first port of call with regard to seeing exactly what disk[s] layout and parameters we are dealing with.

As mentioned, make sure that ALL the text in ALL the columns is visible and showing the whole window.

Now UPLOAD a screenshot of your partitions using one of the following methods . . .

> How to Post a Screenshot of Disk Management
> How to Upload and Post Screenshots and Files at Ten Forums

As a Toool for managing the disk[s], I, like many others, prefer to use MiniTool Partition Wizard [ FREE ]. It has always intrigued me why MS hasn't developed something along the lines of MiniTool Partition Wizard, but that is another story.

I hope this helps.