You didn't state the make and model of the particular laptop, but there should be recovery discs available (or you should have made one) to restore the laptop to factory settings.
I encountered a nasty virus around 6 weeks ago. Have successfully removed it and Malwarebytes and Webroot scans consistently find no lingering problems. However, the laptop is still sluggish and I have gotten some .dll file errors. Specifically eappcfg and corevideo. Can someone recommend a few products I can purchase to help me restore the files that were corrupted by the virus?
I really appreciate any assistance I receive. Thanks.