|First of all, you should delete all temporary files.|
Start > Run > Type TEMP click OK. Delete all.
Start > Run > Type %TEMP% click OK. Delete all.
Start > Run > Type prefetch click OK. Delete all.
You should run disk cleanup utility.
Start > programs > Accessories > system tools > Disk cleanup.
Tick mark all the boxes and click OK.
You should delete optimize internet explorer.
Open Internet explorer and Go to "tools" menu > Internet options. Delete cookies, Delete files, browsing history.
Select content tab and click on clear "SSL State". In advanced option click on "Restore defaults".
Try to download and install Malwarebytes.
Disable all unwanted startup and services.
Start > Run > Msconfig > services - disable all unwanted services from the list. Then select Startup tab and disable all unwanted startup from the list.
You should update all security software and uninstall all unwanted software or program through the Add/ Remove program.
Scan your computer with Malwarebytes.
And run disk defragment utility.
Start > programs > accessories > system tools > Disk Defragment.