So I have this Dell Inspiron 5150, which are notorious for having hardware failures. This particular laptop only worked occasionally. The original user thought it was a heating issue, definitely a common problem with this model.
However, this laptop is actually a victim of a bad RAM seat. The DIMM B bus is going bad, and has cost me a memory module. It took a while to diagnose but the main thing I noticed that lead me to the RAM was the intermittent failures both in booting and freezing while running.
I began to get the message, "The amount of system memory has changed. Press F1 to continue..." And after that the piece of RAM in that slot started to have read errors in some sectors. I upgraded the RAM in DIMM A with a 1GB stick and haven't had a problem since. The DIMM B slot remains empty.
While troubleshooting the hardware I also found out that the memory slots are directly connected to the motherboard and would require me to replace the main board in order to fix it.