I am total tech idiot and having trouble with external hard

I have a really nice laptop i like using it is an older dell xps but my power cord and adapter was fried by a power surge through a power bar and i cant afford a new one right now. I can still use my laptop for about an hour at a time on the battery before it dies. I have a adapter from an older dell laptop that i can use to charge the battery but is not a high enough voltage to run the laptop and was advised against using it to run the computer only to charge battery when it is off. My husband has a laptop as well different brand sony vaio about 4 years old and I am more comfortable working on mine plus he wants his when he is home. So i installed scrivener on both laptops and figured i could use the external hard drive to move project back and forth between the two but must be doing something wrong. I keep getting permission errors i tried changing permissions on back up and now ii cant save from the original source but can load to my laptop now. It is such a mess and so confusing what am i doing wrong? Is there some setting i need to change on my computer or in scrivener to have this work better? The operating system on both computers is vista of a comparable age.

did i mention i am new to scrivener as well downloaded the nanowrimo trial version yesterday.

nothing to do with Scrivener but you can find power supplies for laptops for about $6 bucks on amazon. My BF has an old IBM thinkpad and its power supply died a couple of weeks ago. He got the exact specs from the old one, did a Google search found one, got it in two days.

It’s not you – Windows can be a bit awkward (to use a technical term) about files on an external drive that were written by a different computer – I think at least by default it doesn’t have write access to them. Alternatively, if you have internet on both computers you might consider syncing the project via something like Dropbox instead. It can work very well as long as you make sure to let it finish syncing before you close down one computer and before you start working on the other one.

This actually saved my bacon once when my laptop power cord died during NaNoWriMo a couple of years ago – I only had to wait a couple of days for the replacement, but it would have been a pain not to have access to my project.

I don’t know about that. I transfer files back & forth routinely and so does my writing partner Scrivener FD, Photoshop, Word, etc. No problems