Just looking for some advice for my current situation that arose out of my impatience. For a month I've been meaning to reinstall MacOS on my 4 year old Macbook Air with High Sierra - I noticed a very noticeable slow down when going to Mojave. I didn't have a USB stick so decided to use a micro SD card in an adaptor for my install drive! I know! Well I format my disk and start the install, I get an 'Your Mac had to restart due to an error message' which I assume is because there's something wrong with the SD card. I haven't had one problem with the computer before. My problem is my only Mac is blank and I my boot device is broken. I have a PC. How can I get my Mac back online? I live in central London, do the Apple stores still sell USB boot drives? I can't find them on their website. Preferably, I would use my PC to create a boot drive. It seems getting hold of the OS is not possible unless I use someone else's link (no thank you!). Thanks for any advice.