Error after installing K-lite Codec pack

hello
I have encountered serious problems after installing K-lite Codec pack Version 10.8.0 Basic on my HP laptop - windows 7 home premium - 64 bit
before installing it i was able to watch video files by kmplayer and WMP but now they dont respond to playing any format of videos, or they hang.
some other parts are also faced some problems, such as; windows gadgets stops working when i click on it, troubleshooting stops working and ...

i have also tried to restore the system to an earlier time before the installation of codec but it didnt solve the problem.

please help me how i can solve this problem

First of all, you should never use system restore to remove a program.You should use the uninstaller of the program. System restore is something you use as a last resort or in case of driver troubles.

I highly doubt your problems are in any way related to the codec pack. Not just because nobody else is having these symptoms, but also since they continue after the system restore, and lastly because you are having issues with program that do not even use codecs.

A common cause of these kind of freezes and hangs is bad (read: damaged) sectors on the harddrive. Open Explorer, right-click on your harddrive, go to properties, then Tools, then start the Error-checking. Enable the option "Scan for and attempt recovery of bad sectors". Then reboot the computer. It will perform the harddrive scan before it loads Windows. The scan can take quite a long time, one or two hours.

Another cause can be damaged system files. You can scan (and usually fix) that with this command:
Start > Accessories > Command Prompt *right-click and run as administrator) > type: sfc /scannow

Exactly when did the problems start? Fresh Windows updates were released two days ago (second Tuesday of each month). Those are sometimes a bit buggy.