How to free up space on my C drive? I need at least 8GB.
I suggest keeping any programs that give you the option to install them on another drive so your c drive stays clean and least cluttered.
You can also try moving the Swap File (pagefile) to another partition, moving your My Documents folder to another partition, or, if your C: drive is not using the entire disk, you can use a program like Partition Magic to non-destructively resize partitions to shrink a non-Windows partition to add its free space to C:
You should remove unnecessary applications that are currently installed on your hard drive. You can do this from the Windows Control Panel by going to Start->Control Panel->Programs & Features or it may also be called Add/Remove Programs if you're on Windows XP.
From there, sort the installed programs by size and remove the ones that you know you installed and no longer need. If you're unsure of what an application does, do not remove it or research it first and decide whether you need it or not.
All of the above suggestions are great as well. I would additionally, after removing all the applications I no longer required, run CCleaner.
6 Ways To Free Up Space On Your Windows Computer
Excellent suggestions from Bruce & Hovsep. CCleaner would be my first choice too (along with Wise Disk Cleaner if I really wanted to squeeze every bit of space out of the HDD). Concentrate on deleting temp files first, and only continue to other options if necessary.
Treesize, WinDirStat or Space Sniffer (my personal favourite) are very good in showing you graphically what takes up a lot of space on your computer and home in on possible folders/files to delete. You need to use it carefully, however, as the decision on what to delete is yours and yours alone!
Another thing you can do is to compress the drive, or certain folders within it. Usually it's best to only compress folders you don't use regularly (e.g. system restore backup files) as expanding the files to use them will slow the computer somewhat.
scan the partition and you get size of files, see which one is big and not important
You can use CCleaner to get rid of a lot of the junk on the system. Temporary files tend to take up a bit of space, but if you check the option to remove the hotfix uninstall files as well, you will most likely get a big chunk of space back.