This is in response to the PM you sent me.
Use the new upgraded HDD and use the recovery (re-installation) CD and reload the OS.
After you have done that and the computer is running, click on the 'Start' button and then select 'Windows Updates' - download and install the updates. Then do the customary 'Restart Computer'.
After doing the above, do a complete backup on to an external HDD. This is mandatory and just makes good sense. Along with the Backup, create a 'Windows Repair Disk (CD/DVD). You will need a CD/DVD RW Optical drive for this. Most laptops have this; not all desktops.
Hope you have a good anti-virus program.
All this is time consuming, so please be patient!