"Windows Explorer has stopped running" on starter! Please help!

Before I start, i should say im new to this website, so if this is the wrong place to post this, im sorry.
Ok, so for the past week or 2, I have been having serious problems relating to windows explorer! Every time I try to start up my laptop I receive an error saying 'windows explorer has stopped running!' In the error box there is the option to 'check online for help' and to 'restart explorer.' Neither of these do anything as they only make the box vanish then reapear. If i click the X, the error vanishes for about 3 seconds then reapears! The only way i seem to be able to fix it is by waiting a little and it goes away after i click the X.
When this error is 'active,' none of the desktop items load and i can not click on anything on the tool bar apart from when i click the X and the error is off screen. I can also access task manager and i was suggested to try starting a new task and typing 'explorer.exe' which sometimes works.
Another part of the error seems to be that whenever i try to open anything in my documents, it takes an extremely long time to load. This is even worse when i try to open a video as the sound plays but the video runs slowly (skips several frames.) although games and websites seems to work fine!
Please recommend something to fix it, i have tried both virus and malware checks and its come up clean, and i need my laptop next week as im going to be doing a college course in computing.
Thanks in advance!

Carl Lawrence said:

Have you tried system restore? Also post all of your PC specs please?

I have not because im cautious of doing so since last time i did system restore my hardrive became corrupted!

Since your system is unstable work through these steps for Troubleshooting Windows 7 Failure to Boot to disinfect, check System files and System restore from disk if necessary, leading up to a possible Repair Install as a last resort before running Factory Recovery or Clean Reinstall.

If the system becomes stable enough after any of these steps to work from desktop, then continue with these Troubleshooting Steps for Windows 7 since you won't need to focus on repairing Win7 boot.

If you'll give feedback on the steps as you go we may have different suggestions based on what you report.