my C: Drive is showing Full, i don't know why

I’ve recently brought my desktop computer and I don’t have much experience of using computer. All my application are open very slow and my c drive almost completely full. I’ve 80 gb hard disk and it shows only 5 gb hard disk remaining in my system, in which windows(20 gb), users(40 gb) occupy space, where is remaining 20 gb ? . I don’t know what’s wrong with my computer. Are you have any idea where is the remaining 20 gb hard disk. Please tell me how should I resolve this issue. Please suggest me some solution to this. Please help me.

You can use cleaner to make clean your hard disk. Double click the ATF cleaner.exe and run the program. In the main select all, click empty selected button. Try to do this if it works for you then good and if not, then try to defragment your drive. Defragmenting will free all the space which is occupy in your hard disk un necessary. All the data you put on a hard disk is stored in a different location and many space remain in between two memory location. Defragmenting will free that space which is located between two memory location.

You have to check manually that, is there anything which has taken a more space. Check your recycle bin. Right click the recycle bin, click properties, move the slider from 10 % to 3 %, then click apply and ok. Now your recycle bin take very few space in your hard disk. Right click to my computer, click properties, go to system restore, move the slider from 12 % to 3% then click ok. You have to delete everything which is inside the of C:\WINDOWS\TEMP. delete everything inside a C:\DOCUMENTS AND SETTINGS\(USERNAME)\LOCAL SETTINGS\TEMP. these two temp folder contains junk data, you have to remove all the data from this folder.

Check that, is there any virus in your computer ?. there are viruses which occupy lots of space of your hard disk and also make duplication. So, scan your computer for virus, if you don’t have a antivirus get it from your friend and install in your system. you can also download a antivirus software from internet but you’ll get a trial package. Trial package will work for one month in your system. you can remove the virus from this trial package version. Install that antivirus in your system and scan your system. once you have scan your system the antivirus will detect the virus automatically and remove it from a system.