Did you know that 5% of hard drives die in the first 18 months of use? It then levels off for a while and starts dropping significantly after the 3 year mark.
This is why, whenever possible, your hard drive's health is checked while it's on the workbench here. It's all well and good to remove that virus but, if it's handed back with a undiagnosed dying drive, that's like splinting a broken finger and missing a cancerous lung.