Yeah, you need to charge a minimum $40 to $50 maybe. Usually home users pc's are so bad the biggest portion That I run into, will barely run and very often they won't even boot. Full of trojans, viruses, spyware, crap free programs and screensavers. Many I have seen have never had a windows update or service pack installed. They don't have a virus scanner, or it hasn't been updated in the 3 or 4 years they have had the damn thing.
So then if its a hewlitt packard for instance, you have to apply updates from them before updating sp2 and on and on. Then you get the ones where a friend that knows a lot tried to fix it, but couldn't. You can spend hours and hours sometimes. They never did any backups and most of the time don't even know what that means, but you better hope you don't lose any files in the process, if you end up reformatting. Like I know what the hell they want to keep.
Oh yeah then 1 to 2 weeks later they bring it back and say it still isn't right and want you to fix it fro free. Guess what, they downloaded the same crap right back onto the pc after you tell them not to. Also, endless calls for free phone support. Tell them they need to bring it in.
Very frustrating to say the least. Better money in businesses, but still a lot of the same crap. They can't see spending any money to fix a pc when they can go to Best Buy and get the 299.00 after rebate special/ with monitor, then wonder why it is a piece of crap.
Anyways, better have some set policies before you plunge into it. Good luck! your gonna need it!
EDIT: listen to these folks. Its posible that if you uder charge too much, they will take the business to geek squad and geek squad will charge them plenty.
I have seen shops charge people like $300 to clean one up and optimize a little. So yes, charge more than $10