First step

My first step would be to look at the Acrobat rendering options, especially with an older video card.

1. My first step would be to stop the hardware rendering which you can find under Edit/Preferences/3D and Multimedia:

2. You could also change the Preferred Renderer (from Directx to Software) but I'm unsure what other implications that might have - it might be overall slower, but eliminate the 'hangs'.

Next Steps - disabling unused add-ins

WP_ gave the info for this earlier so I'll just add it here from WikiHow

1. Go to Acrobat -> Help/About Adobe Plugins
2. From the list of Plug-ins:
3. Decide the plugins you need, note down the File names for those you don't:
4. Close Acrobat. Browse to C:\Program Files\Adobe\Acrobat 6.0\Acrobat\Plug_ins and locate the files of the extensions you don't require, move them to another folder (so you can restore if required).
5. Running Acrobat will now not load any add-ins you have moved, this should speed up performance and possibly remove add-ins which are causing any problem.

Extra tip: Double clicking to run Acrobat while holding down Shift opens the program without loading any add-ins for that particular instance.

Here's how I solved it:

Open the pdf in chrome, print it to pdf. You can now edit it.