Hi,
Basic steps for increasing C: via portal are:
- Stop the VM
- Resize the disk to larger size, save
- Start the VM
- Connect to VM via RDP, right-click on Start--Disk Management
- In Disk Management, right-click on C: -- Extend Volume, step through wizard
When you are in the portal sometimes it will show the old size and you just need to click Refresh.
If the above was helpful please click Accept Answer. If you are still unable to resize the drive, please let me know at what step the process is failing in a comment.
Thanks.
-TP