At least you weren't like my Dad and actually called the number! He talked to someone and then actually let the guy remote into his computer!
After a few minutes, the guy said he can remove the "virus" for $300. My Dad balked at that and didn't give him any more info, but before he could disconnect the remote connection, the guy had deleted his MS OFFICE programs...
That's all the guy ended up doing, but dang.. My Dad is a retired Mechanical Engineer from HP and did very well there, but when it comes to computers, he knows nothing... Which is ironic having worked for HP... But, he dealt with the plastic injection molding part of HP for printers...
Anyway, he got lucky in only losing Office... I restored it for him the next time I visited.. Parents... ha, ha!
Mitch