replacing the hard drive itself is fairly easy, there should be a panel on the bottom of your laptop that is screwed in, remove the screws, then the hard drive will be screwed down to a bracket. remove the bracket, then the drive will slide out, then you simply put the new drive in, and replace the bracket and the cover. pretty straightforward. (make sure you do this on a non static surface and ground yourself before touching any components) Usually between 2-6 screws for the cover, and between 2-6 screws on the bracket (by bracket, Its usually two pieces of thin metal held together by a clear piece of plastic, 2 screws to hold the bracket in place on the laptop, and 4 holding the bracket onto the hard drive)
reinstalling the OS is somewhat more difficult. The recovery "drive" is actually a recovery "partition" on the existing drive, and it will be removed. I see you have made a recovery drive on the stick-which is good. Now, if the engineer who designed the laptop had any lick of sense, all you should have to do is insert the USB drive, and turn it on, and it should boot up off of it. However, seeing as computer manufactuers, especially dell, are not well known for having any sort of common sense, you may have to access the BIOS (usually F12 or the DEL key, but may also be the f2 or f8) and find the boot order, and change it so the USB device is at the top of the list. beyond that, windows should guide you through it step by step.
Primary system: Motherboard: ASUS M4A89GTD PRO/USB3, Processor: AMD Phenom II x4 945, Memory: 16 gigs of Patriot G2 DDR3 1600, Video: AMD Sapphire Nitro R9 380, Storage: 1 WD 500 gig HD, 1 Hitachi 500 gig HD, and Power supply: Coolermaster 750 watt, OS: Windows 10 64 bit.
Media Center: Motherboard: Gigabyte mp61p-S3, Processor: AMD Athlon 64 x2 6000+, Memory: 6 gigs Patriot DDR2 800, Video: Gigabyte GeForce GT730, Storage: 500 gig Hitachi, PSU: Seasonic M1211 620W full modular, OS: Windows 10.
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