There have been a lot of suggestions for you now... thanks to everyone who contributed. But, this can be quite confusing.
Lets keep things simple, and take things the easy and slow way, to avoid any mistakes.
Now, that you have told about your disk partitions, it should be clear that partition manager softwares are not needed for now.
The first partition EISA(Extended Industry Standard Architecture) should not be modified or deleted. This partition contains operating system files, and drivers, that are useful in case you need to restore your system in the case of any failure. It is used for system recovery... so you should definitely leave this partition alone, and not do anything with it.
From what you wrote about the partition details, it seems that this partition is empty. Its quite confusing to me. It should not be empty.
I am also not quite clear about the F: partition which is empty too.
Can you please take a screenshot of your Disk Management, and post it here... so that we can have a look for more better understanding.
Now, your C partition is having 176 GB, and this is the partition about which you are mainly concerned.
So, for this, first I would advise you to download
CCleaner, which was suggested by Jojoyee too. This is a software, which cleans files which keep accumulating on the system as you work on it. These files are junk, or temporary, and not required by your system. Choose the default options of CCleaner, and just analyze and clean the files. This should free up a lot of space, if you have never used CCleaner before, on your system.
Please do not use the registry cleaner of CCleaner. Only the file cleaner with the default settings.
Then, after that, next step would be to use the software: WinDirStat, or TreeSize(Links to their sites given in earlier post). These will tell you in a graphical way, where the space of your hard disk is being used.
I think this is what you need to do for now. Reply back after doing this, and then we can take it further, if you still have more questions, or this does not solve your issue.
Then we can look at more complicated things like system restore files, or other things. Don't worry about them for now.