My phone screen is broken and i can't access my data etc. on it anymore since touch and screen don't work. I'm wondering if it's possible to plug it onto an pc and stream the screen to my pc (without an app installed on the phone.) just like downloading an os from pc to android. It's a samsung galaxy s advance. any help would be greatly appreciated!
If its just data you are concerned about then you don't even need to mirror your phones screen on your computer. You can use a development tool called ADB, this will allow you to simply connect your phone through USB and access the filesystem.
There is plenty of documentation online about ADB, but if you need any specifics for what to do let me know in a comment.
While using adb (see its tag-wiki for details) is a good idea, you would need to have usb-debugging enabled to be capable of using it. There are ways to do that (see our broken-screen tag-wiki), though. But there are also alternatives:
For the display, you could use HDMI (or an HML to HDMI adapter) to have it "mirrored" to e.g. your TV or Laptop. For input, you could use an USB mouse/keyboard, assuming your device can operate as "OTG host" (there are some apps to check that – but checking this way would be a chicken-and-egg thingy; easier to just go ahead and try the real thing).
If all those steps work out, you should have a full display and input back, and could do with your device whatever you wish: Streaming, copying, using it as a "NAS", Webcam, whatever.