I'm using Windows 7 and have an external hard drive
I'm using Windows 7 and have an external hard drive attached. When I start windows I can access the files fine, however toward the middle of the day it won't allow me to write to it or open any files. I'm not sure what changed. It's really bad because we use this external hard drive for business.
Have you tried accessing it from safemode? Also, please try connecting it to a different USB port of your computer.
Also, if you are using a USB cable to connect it to your computer, pls check that also. If you have any other USB cable pls try to connect using it
Possible causes of this issue are corrupted file system in hard drive, bad usb cable or usb port and issues with the external hard drive. If the above steps not worked, you may try copying the files from the hard disk immediately after detecting it. Then, you may format that external hard drive.
If you have any questions, please ask me. I am very happy to help you. I understand how frustrating this kind of issues.
If you have any other computer, you may try connecting it to that computer.
In rare cases, Viruses also causes this kind of issues. If your computer have a good anti virus to scan the external-drive, please try to scan using it