As a guy, you may often find yourself eager to share your (probably superior) knowledge of computers with women--but might be intimidated to actually walk up to a girl using one and strike up a conversation. You shouldn't be--this is the best time. Firstly, women usually lack a deep knowledge of computer security and by helping them out, you'll be doing them a favor even if they don't appreciate it at the time. Secondly, women using laptops are often frustrated with the WiFi or their connection speed and if you can help out there, that's at least a "coffee date!"
You might even be in a coffee shop to start with!
These are the steps you should take when approaching a woman on a laptop.
Shoulder-surf - Try to do a passing run behind her and see if you can tell what she's working on. Also, make sure she's using a Windows computer. Things could be embarrassing if she has, like, a Linux system or something. If she is doing email, surfing celebrity gossip, or posting of Facebook, you can definitely approach her. If she's writing a term-paper or working, only try this if you are familiar with the subject at hand.
Adopt a confident tone and posture - The approach should indicate to her she's dealing with someone who can handle themselves. Don't be aggressive but do be out-going and high-energy. Move in close. For now, you should let her keep the laptop between her and you so she will feel safer, like she's in a little castle with a wall. When she shifts the laptop to "let you in" that's when you know you've made your score.
Ask her if she is aware of the latest Cyber-Virus threats - While this constantly changes, you can spice up your opening line and add some urgency by asking if she knows about the latest 'Zero-Day' that was 'just announced' or if she's see the warnings about 'social media ransomware.' These are technical terms that should alarm but not frighten her. You're also ready to help--that'll help her feel confident.
If she is guarded - If she's interested in the conversation right away, install an anti-virus, a spyware checker, a firewall, and maybe see if her operating system needs an update. A reboot is a good time to make social chit-chat. On the other hand, if she is guarded, make sure she knows the potential seriousness of the threat. Tell her that the bot-nets have started hijacking social media accounts and making them public for everyone plus locking out the users and encrypting the pass-codes so they can never get them back. Also tell her that they can get her bank account data out of cookies even if she's never done any online banking. This isn't strictly true--but it's how we should all behave anyway.
Making the play- Tell her that you can lock her system up tight and have a bunch of handy links ready to go with. Maybe on a thumb-drive. This could take about 30 minutes. If she already has some of that software, it probably came with the computer--but make sure you tell her your stuff is much better.
WARNINGS / RISKS
Gaming / Power Laptops - RED FLAG. If she has a gaming laptop, DO NOT APPROACH HER. You don't need the hassle. Gaming Girls are young ladies trying to break into the male hobby because they want to feminize it--or they already have boyfriends. Either way, this is not your scene.
Linux - MASSIVE RED FLAG.In the event of a woman using a Linux laptop, you should AVOID AT ALL COSTS. Firstly she is probably a lesbian--and not the cute kind. Secondly, she fancies her computer knowledge to be above yours and considers herself safe from cyber-viruses.
MacBook - Yellow Flag. MacBooks are fine systems but they're costly and less prone to get viruses. This means that the girl will likely feel safer. Also, they tend to be used by artsy types, which is fine, but you're looking at high-maintenance. Unless she has some cute decals on it, the MacBook is kind of a "stay away" signal.
Glasses - YELLOW FLAG. Lots of people wear glasses, but in the case of a girl on a laptop, glasses either means she doesn't care enough about her profile to wear contacts or she is trying to affect a kind of 'librarian' / nerd-girl look. If her hair is also up, DO NOT APPROACH. However, if the glasses are cute you could just be dealing with a yet-to-hatch social-butterfly.
Feminist Sites Up - RED FLAG (ADVANCED ONLY). If during the shoulder-surfing stage you see any feminist sites up on her system, you should probably call it off. These include Wonkette, Feministing, or Jezebel. If you have advanced Skillz, though, make a go of it. Sometimes they just want to be challenged so they can "keep their dignity." NOTE: Mommy Sites should be considered a YELLOW FLAG for obvious reasons.
Feminist Decals - A lot of girls deface their computers with various decals and stuff. This is decoration and accessorizing so it's fine for them but keep an eye out for any political symbols. This includes the Anarchist A, the Venus-Fist symbol, or other things. If she has a bunch of band logos you don't recognize that's a YELLOW FLAG. On the other hand, cute decals like Hello Kitty are basically an invitation to be chatted up.
GO OUT THERE AND CHAT 'EM UP!
You don't have to be under-confident. Girls on laptops are a great target for some flirting and chit-chat. You also get a girl who other guys--less confident ones--won't approach which makes your job a lot easier! Go get 'em, tiger!