Depends on the price range you are looking for, i have found some in Wal-mart for an acceptable price, so you can get one there or at K-mart or Target as well.
The average cost of laptop power adapters is about $80 to $100 USD. You can find more affordable power adapters, but the quality and life span will not be as good.
First, one would need to know the exact model of the laptop. Many different places sell laptop power adapters such as Best Buy, Office Depot and even places like Walmart and Target.
Amazon marketplace at amazon.com is an excellent website to buy a laptop adapter. Amazon has a wide selection of laptop adapters for low prices. Amazon offers a selection of brand name laptop adapters.
What voltage is used in Dell Laptop AC Adapters depends on in which part of the world the laptop gets bought. Europe for example has a diffrent voltage then the USA.
Car charges for a laptop can be found at BestBuy, Walmart, Radio Shack and CompUSA. Used chargers can be found at Amazon and eBay for affordable prices.
Yes most laptops have car chargers that can be purchased.
Wattage, voltage, and connector.
The power adapter need 230v, 50Hz supply
The security for a laptop is no different than that of the standard computer. In both cases, I've found that Norton has one of the most affordable and thorough systems for anti-virus out there. There are many free ones, McAffee and other, but the quality of Norton is worth paying for.
A dell laptop keyboard can be found at Best Buy for around $10-$60. If still on warranty, I suggest you go back to the shop and get your keyboard repaired.
They do make universal USB serial adapters. They are very affordable.
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