Computer running slow at Wolston in Warwickshire

We are now with a customer on Main Street at Wolston in Warwickshire. We are here because the customer has reported that their computer is running very slow, its a Compaq Presario laptop computer running Microsoft Windows Vista we cleaned up the computer by editing the registry and running a Malwarebytes scan which helped matters, but it was supplied with only 1 Gigabyte of RAM and Microsoft Windows Vista really needs 4 Gigabyte of RAM or more to work smoothly, We have recommended the customer to buy a 4 Gigabytes RAM upgrade for which we have supplied the part numbers.