Hi there! I understand you're having trouble signing in to the Delmarva Power app, and your internet or browser URL settings don't seem to be the problem. Let's work through this together to figure out what might be causing the issue.

First, just to confirm a couple of things:
- Are you seeing any specific error messages when you try to sign in?
- Is this issue happening on the app or the website, or both?
- Have you recently changed your password or account details?

Meanwhile, here are some initial steps we can try that often fix sign-in problems:

1. Clear your browser cache and cookies: Sometimes, stored data can cause issues with logging in. On your Windows device using your current browser, you can clear cache/cookies by going into browser settings → Privacy or History → Clear browsing data.

2. Enable JavaScript: The Delmarva sign-in requires JavaScript enabled in your browser. Double-check your browser settings to ensure JavaScript is allowed.

3. Update the browser: Make sure your browser is up to date, as outdated browsers can cause compatibility issues.

4. Try a different browser or device: To rule out browser-specific issues, try signing in from another browser (like Chrome, Edge) or another device if you have one.

5. Reset your password: If you suspect your credentials may be the issue, try resetting your password through the "Forgot Password" link on the sign-in page.

If these steps don't solve the problem, there might be an issue with your account or the system. In that case, you may want to contact Delmarva Power's Customer Care directly for assistance.

Let me know how these steps go or if you get any specific errors—I’m here to help! Are you satisfied with these initial suggestions?