[help] Windows 10 install failed

[Uros Grabovica]

Hello and good afternoon.
Guys, I have an issue, and I didn't know where should I post, so since this is very popular forum, I decided to post it here, with hopes of quick replies.
Anyhow, here's the problem, I own almost 10 year old PC, bought in late 2006, I upgraded it ever since, but original hard drive stayed the same, it never failed so I never changed it. Anyhow, HDD has 160GB, it's split in two partitions.
Problem is in partition C, Windows takes 40.2 GB right now, with windows 10 installation downloaded I suppose, anyhow total space left is like 7GB...
I tried to update and windows says update failed, I suppose because you need 20GB free HDD space, I removed all my games from C, yet I can't make 20GB, it's just shit ton of programs.
I wish to make clean install and remove all documents, but I can't install windows 10 on C, does anyone have a solution how to overcome this problem?
Can I force Windows 10 to do fresh install on D partition (it has 50+GB free space)
http://oi58.tinypic.com/10qjqtj.jpg
P.S: I apologize if I broke any rules, I tried my best to follow the rules on the right and I'm kinda desperate.

 

[USAFRet]

1. I don't believe you can force it to install to the D for the Upgrade.
2. 40GB is too small for one OS, much less trying to upgrade it.

Solution? Scavenge some space from the D partition.
Shrink that existing D partition, and extend the C partition into that reclaimed space.