Dear yanwh00,
I'm Dyari. Thanks for reaching out. I will be happy to assist you in this regard.
A-There is no Microsoft native option or tool to combine two or more partitions directly or else you should use a third-party tool.
However, the best way to combine them without losing data is:
1-Backup all the data in the partition E on an external drive or just transfer all the data to D.
2-Right click on Start > Disk Management
3-Right click on Partition E and Delete it in order to become unallocated partition with black label on it.
3-Then you can extend Partition D.
4-Retransfer all the data on the D drive after been extended.
Be noted that you can only merge two adjacent partitions on the same physical hard drive. Also, If there is any other partition between them, you are not able to extend partition D.
https://www.tenforums.com/tutorials/96732-exten...
B-You can run TreeSize which is a free tool to detect which file and folder has occupied the biggest size in the C: drive. After running this tool, you can select which file is unnecessary and delete it:
https://www.jam-software.com/treesize_free
Also, you can follow the step provided in the link below to free up drive space:
https://support.microsoft.com/en-us/windows/fre...
Please let me know if you need further assistance and keep me updated.
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