Your system files might be corrupted in some way, try System File Checker. If it discovers that a protected file has been overwritten, it retrieves the correct version of the file.
Do as follows:-
Click Start (Windows Icon)
Type cmd in the search box
Right click on the cmd program and click on 'Run as administrator'
Type sfc /scannow
Press enter
This will take around 5-10 to scan all the system files.
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Also you might have lots of programs running in the background which you don’t use, you need to disable them, so that they don't load when you turn your pc on.
Do as follows:
Click Start (Windows Icon)
Type msconfig in the search box
Click on the msconfig icon to start program
Click on Startup [at the top]
Now all those programs listed are running in the background, you need go through them and untick the ones which is not required. Leave the ones which is labelled Microsoft Corporation, Intel Corporation, Sun Microsystems Inc. Whatever antivirus checker you are using leave that as well.
There are also lots of programmes running under the Services Tab, you can disable some of those too, again don’t alter Microsoft Corporation, Intel Corporation, Sun Microsystems Inc, Antivirus program.
Once you uptick the programs you don’t require at start-up, click Apply.
Restart your system.
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If you are using Internet explorer, Reset it.
Go to Control Panel, click Internet Options,
click Advanced [on top], then click on Reset box. click Reset again, then finally click OK