Hello there my tech savy, site friends. So recently I decided that I should get another external storage device, and i thought the best time to buy would be this Cyber Monday. However I just realised that insted of adding to my desk items, that I could just swap out the internal HD of one of the 2 devices that I have. Then as wend to get one of them I realised that I have actually have 3 external drives or 2 notbooks that can be upgraded. Now I am not up on all the compatability of drives so, I was hoping I could get some help here. Now I'm not compleatly computer hardware illiterate. In fact, I use to build systems for myself and friends , and even a company that I use to work at. However the last time that happened was when Windows XP was the newest OS. So I can to the mechanical work, I even pulled out my old wrist grounding strap. So I have 3 external hard drives that are practically full and one notebook whos internal drive is nearing full too. I was just searching online and they got some great deals, but im not sure what I can or should get. Let me tell you the hardware that I have: 1st - Western Digital Net Center 5105A, MDL: WD1600P019. (I think it was a 500GB, and I stoped using it when one day I went to access it and everything was gone and the capacity being displayed was two hundred somthing. Mfg. Said it was probably a HD failure and I was 2 months passed warrenty. ) 2nd -Seagate Free Agent Desktop 250GB, P/N: 9NK2AE-500 (Works fine, it's just 6MB from full) 3rd - Western Digital, My Book, Essential 1.5TB (Works fine, it's just 3GB from full) Current Notebook computer - Toshiba Satellite L505D-LS5001 (Works fine, it's just 7.3GB from full. 250GB drive) I am going to be moving to another notebook computer. Wich is a Toshiba Satellite C655D-S5331. It was bought in December 2011 and the box never opened. It was believed stolen, but was found this weekend in the back of a storage closet. My brother just told me about it and is giving it to me. Sooooo, these are some drives that seem like a great price. And im not sure if they fit any of my devices. 1) - Priced at $99.99 Seagate Desktop HDD.15 ST4000DM000 4TB 5900 RPM 64MB Cache SATA 6.0Gb/s 3.5" Internal Hard Drive Bare Drive 4TB, SATA 6Gb/s NCQ For desktop or home server use Store active archive data Outfit direct - attached, entry-level external storage devices (DAS) 2 years limited warranty 2) - Priced at $39.99 TOSHIBA PH2100U-1I54 1TB 5400 RPM 8MB Cache SATA 3.0Gb/s 2.5" Internal Notebook Hard Drive Retail Kit Works with Serial ATA enabled notebook computer Read/Write cache for increased performance Internal shock sensor and ramp loading technology to help protect your drive 3) - Priced at $54.99 TOSHIBA MQ01ABD100 1TB 5400 RPM 8MB Cache SATA 3.0Gb/s 2.5" Internal Notebook Hard Drive Bare Drive Eco-conscious Design, MTTF of 600,000 Hours Advanced Format 512e 3 Gb/sec, 5400RPM 3 years limited warranty Now I would really love to just upgrade one of my 3 desktop drives, the WD net center is nice because I liked how I could always access it from different devices via wifi on my network, but I understand if I can't, because it's too old. Economically thinking, I would love to be able to put an inexpensive ($100 or less) 3 or 4 TB drive into the My Book, and move its 1.5TB drive to the Net Center, but again, it might be too old. I wondered if I could get that 4TB Seagate and put it into the Free Agent case. Also if can get the Toshiba 1TB drive, and put it into one of the toshibas I have listed. It's real cheep. Or maby somone seen a more appropriate deal for me. Anyway, my head is starting to hurt thinking about this. Lol Somone Help me please. and as always , please, and thank you for being nice.