This is some standard guidance that addresses the most common issues afflicting Flash in Firefox. I'm sure you've seen some of it in other threads, but just in case:

(1) Make sure all recorders/downloaders that interact with Flash media are as up-to-date as possible, or disable them.

(2) Disable hardware graphics acceleration in Firefox and in Flash

(A) In Firefox, un-check the box here and restart:

orange Firefox button (or Tools menu) > Options > Advanced > General > "Use hardware acceleration when available"

(B) In Flash, see this support article from Adobe: http://helpx.adobe.com/flash-player/kb/video-playback-issues.html#main_Solve_video_playback_issues

(3) Disable protected mode (Windows Vista/7/8)

See this support article from Adobe under the heading "Last Resort": Adobe Forums: How do I troubleshoot Flash Player's protected mode for Firefox?

By default, Firefox can submit your crash data to Mozilla so it's available for analysis by the developers and, if you can give us the links, to volunteers here. To find out how to locate and share a few recent links, check out this article: Troubleshoot Firefox crashes (closing or quitting unexpectedly).

Here's an update: I made sure to disable hardware graphics acceleration in Flash and I decided to downgrade my Flash Player to 10.3. I wanted to mention that while I was downloading the .zip file containing Flash, my browser crashed again. The download did complete, but when I checked my Windows Task Manager, CPU usage went up to 50%, and I didn't know what caused it. However, I did receive a message that mentioned something along the lines of "High Disk Usage by: Host Process for Windows Services." If there is some way you could help, feel free to reply back as soon as you're able. Thanks.

Hi halfturretturbo, I'm not sure where you found the Flash 10.3 plugin now that Adobe is no longer supporting it; please be very cautious about the sites that you trust to install software.

The "Host Process for Windows Services" is used for many different pieces of software, some belonging to Windows and probably some third party software. It's hard to know what services are kicking in half way through a download.

If you disable the existing Flash plugin, does that help in downloading the one you want?

orange Firefox button (or Tools menu) > Add-ons > Plugins category

Please also see the above post regarding crash IDs.

I found the old Flash Player from Adobe's archive page. If you see it best for me to do so, I will change back. However, Flash Player 10.3 does not seem to be affecting my CPU in any manner, if what the Windows Task Manager is telling me is correct. When I used the most recent version of Flash, a single YouTube video would use upwards of 60 MB, even when it was not playing.

With that said, I have disabled hardware acceleration for both YouTube and Firefox, which helps keep a consistent performance, but with my internet speed (roughly 60-70 MB per second), runs fairly slowly. If there would be some way to compromise speed and performance for my browser, I would greatly appreciate it. I apologize if I come across as difficult, since that is not my intention, but I still thank you for your help irregardless.

Sorry for the sudden reply, but my Internet seems to be timing out more consistently during downloads. I was trying to update my Adobe Reader plug-in, but the download stopped at the 64% mark. I just wanted to ask for your opinion on the matter. Thanks, again.

I made a mistake on the Internet speed. I meant to say 60-70 KB per sec, not MB. My apologies for the mistake.

Hi halfturretturbo, Flash 10.3 was only discontinued recently, so it's reasonable to use it for a while longer.

Regarding a slow connection, I don't have any suggestions for different Firefox settings. Some of those speed-up add-ons may have made changes designed for high-bandwidth connections. Using or not using hardware acceleration probably isn't a factor either way.

Page load times may be more related to the complexity of modern pages, which include lots of extras like sharing buttons and ads. There are add-ons which help streamline pages by blocking elements. Maybe one of those would help?

I would be willing to take some recommendations for add-ons. Whatever you suggest, I would gladly try them out.

Also, there is something else I wanted to tell you that happened recently. While I was loading my bookmark menu to reach this site, I experienced another crash. However, thanks to Norton Anti-virus, I located the Host Process that was troubling me. It was the svchost file that was located in the folder in C:/Windows/winsxs/amd64_microsoft-windows-services-svchost_31bf3856ad364e35_6.1.7600.16385_none_11b04b481efec48c. For some reason, the file was using over 200 MB of memory. If you know something about it, I'm willing to listen. I appreciate all of your help.

Apparently the WinSxS folder is the folder that contains most of Windows and you don't want to manually delete anything in there... See: What is this folder - - C:\Windows\winsxs?? - Microsoft Community

I have one more question to ask for now. With my computer and Internet connection, would it be better for me to watch YouTube videos with the HTML5 player or the standard Flash player? Also, would using the HTML5 player have a positive or negative impact on my computer's performance? Just yesterday, I was using HTML5 to watch my YouTube videos, and when I found a video that used the regular Flash player, the browser crashed; so, at the moment, I am using Flash for my videos. Respond back whenever you can, and thank you for your time.