The status of this response is Pending and require some modification by the author.
As per the official API documentation, no external app is allowed to schedule and upload the content. Such content is pushed to the users mobile as a draft and then it can be then pushed to the profile. Desktop and the browser based Instagram does not have option to upload the images. So you can't upload the images from PC.
There are some ways around this limitation, which you can try.
You can download the bluestacks Android version and then install the Instagram app. From here you can upload the images to your profile. However scheduling is not possible.
You can use the social pilot to push the images from your desktop to your profile as draft. From here you can publish as required. This can be handy workaround for your current problem. You can use their free plan for uploading the content.
Just like socialpilot, the same feature is provided by the Hootesuite. You have to authenticate your account through their system And push your content as a draft. This way you can upload the images.
These three seems to be the options that are being used by the social media managers. And you can find these helpful in posting on instagram through such tactics.