Windows 7: C; drive full

my C drive is having just 1 gb space free out of 49 gb , i deleted temporary files, and softwares i do not use. and i managed removing around 1 .5gb but the next day it was again full. what should i do. There's a folder named 43e428465ab14b5567d92253 and it needs permission to open , and permission is denied when i try to open, size is 0 when checked in properties .. please help.. is that thing a malware or something

I use CCleaner to delete unused files, keep only the last restore point.
You need to boot from recovery CD to delete those folder with cryptic name.

Filling in your system specs completely would be of great help.

As Layback Bear said, some system spec.'s would help tremendously. With that size HDD I'm assuming its a laptop though.

With a size of "0" I wouldn't worry about removing that file unless of course its proven to be malware , which I doubt. Nugroho made a good point about your restore points, I'd only keep one or two on your size HDD but thats me. If you have access to an external drive move all your personal things to it. (photos's, music, big text files etc. or burn them to a dvd/cd)

A run with Ccleaner wouldn't hurt at all or you could empty your temp folders manually. Just type Disk Cleanup in your start menu, choose whatever drive you want to clean, C in your case, Click o.k.

You could run a few scans for malware also. I recommend Malwarebytes, its free and is highly trusted and recommended.

Welcome to the forums by the way!