Unless you reboot your HTC EVO 4G on a regular basis, its boot animation isn't something you see very often. If you don't remember what it looks like or aren't sure what "boot animation" even means, it's that white, yellow, and gray Sprint/4G/Now Network video that plays on your EVO right before you see your lock screen. Don't spend time trying to picture it now because I'm about to show you how to replace it with something else.
There are countless boot animations that can be found all over the internet (here's a collection of EVO-ready ones if you're not in the mood to use Google) and nearly as many methods to get them on your EVO. Pushboot 3.0 and Boot Replacer will get the job done when you're hooked up to a computer, apps like Boot Animation Changer and Bootanimation Utility will take care of everything directly on the EVO, and the Android SDK and some basic ADB commands will do it without even requiring root access.
Again, there are other ways to do this; there are also other root file managers out there. Root Explorer is simply my personal choice and what I use to change boot animations.
IMPORTANT: As always, if you don't know what you're doing, please don't do it. Or go ahead and do it, but don't hold me or anyone in the comments responsible for whatever happens to your phone.
1. Download the boot animation you want to use and rename it bootanimation.zip. Move to your SD card (anywhere is fine as long as you can find it later).
2. Rename the stock boot animation. You can also delete or move it somewhere else, but I think it's easier to just leave it where it is and rename it in case you ever want/need it again.
- Open Root Explorer.
- Tap system > customize > resource.
- Tap the Mount R/W button at the top.
- Long press on the existing bootanimation.zip that will be listed there.
- Tap Rename and rename it whatever you want. I named mine bootanimationold.zip.
3. Now tap the EVO's back button to get back to the main directory and tap sdcard to find the new bootanimation.zip you downloaded earlier. As shown in the screenshot below, mine is in the download folder on my SD card; yours will be wherever you put it in step 1.
4. Long press bootanimation.zip, tap Move, then tap the EVO's back button to return to the main directory and press system > customize > resource. Press the Paste button at the bottom.
5. Reboot your EVO and enjoy your new boot animation.