When I try to scroll back in messages on my Iphone, it gets so far and then crashes. I asked Siri how to look at my messages on my PC and was directed to download Icloud for Windows. How do I look at my messages?

Hello and welcome to Apple Support Communities, bmdaniels.

If we understand your post correctly, you're trying to read your Message on iCloud rather than your iPhone. We’d like to help.

You can sync your messages between devices with iCloud but it's not possible to view your messages from your PC. This article will explain what you can do on your PC with iCloud:

Set up and use iCloud for Windows

If you let us know more about what's happening with your iPhone we'll try to assist with that.

Thanks for using the Apple Support Communities.

Hello bmdaniels.

The next option would be to restore your iPhone from a backup that was created while the messages were on your iPhone. You can find steps for that here:

Restore your iPhone, iPad, or iPod touch from a backup

Have a great day.

Hello bmdaniels.

Your messages may not be set up to stay on your iPhone for longer than the time frame you're seeing. Tap Settings > Messages. Scroll down to Message History and tap Keep Messages. Select the time you would like the messages to be kept.

Cheers.