Can you do then the following please to remove any corruption within the registry and Hard Drive.
Download CC Cleaner (free) from hereCC Cleaner
(Click Download Latest Version on the top right)
Run it and let it scan and repair your registry.
Once done, restart the computer
Click Start, Run, type in CMD and press enter
A black window will open.
Type in it
press enter and when it has completed, type in
It will give a message "the type of the file system is NTFS cannot lock current drive.
chkdsk cannot run because the volume is in use by another process. Would you like to schedule this volume to be checked the next time the system restarts y/n" Say Y, press enter and restart the computer.
Than tell me if the performance has improved please.