New router didn't improve streaming media problems...do I need to adjust settings?

Hi!
I'm running Windows 8.1, (details below), & I was having problems with streaming media. I watch several bald eagle nest cams daily & the media stream was always choppy, out of sync & looked like it was in slow motion, (even though my browser, (Firefox) & Adobe Flash are up-to-date). I have at least one nest cam on at all times because I need to keep records, & when I try to do anything else at the same time I'm watching a nest cam, e.g. play a game, open my email or just use my browser, the streaming problem got even worse. Since my router was about 4-5 years old I thought that maybe it couldn't handle things, so I bought & installed a Linksys E2500, Dual Band 'N' Router & I expected my problems to disappear. Well, that was about 10 days ago & nothing has changed; in fact at times it seems to be worse. I called Linksys & they recommended their 3rd-party "partner company", "Supportrix", to troubleshoot & optimize, but their fees are way out of my very low, fixed-income budget & also, I'm a bit uneasy when someone wants to do remote control procedures on my PC, (unless they're from my AV program's company!). While I'm far from being a tech expert, I have been using a PC since 1999 so I know & understand the basics...even more important, I can understand & follow detailed instructions from people who ARE tech experts, like most of the people here at Majorgeeks. So, here I am with my problem, a functioning brain & I'm hoping that someone will have some suggestions for me to try. I'd like to do everything I possibly can before I can even consider turning over my PC, albeit remotely, to a company I don't know anything about, (that is out of my price range), especially when it's possible that it's something I can do myself, (with the help of you guys!).
From the limited knowledge I have about these things, it seems to me that there are probably drivers on my laptop that need to be updated, & I'm guessing that there are settings for my new router that could possibly be changed in order to optimize it. When Linksys helped me set it up by phone, they did the basics...just enough so I could get online again, but nothing 'extra' to make the router perform its best. Another problem I have is I'm physically limited due to disabilities, so I can't crawl around on the floor to plug/unplug connections for the modem/router, etc., so I've been avoiding contacting my ISP, (Comcast), because I know they'll want me to plug/unplug stuff to test things; I want to do what I can myself & put off calling them unless I really have to. I ran the speed test from Linksys to check the download/upload speeds & they were different every time. I ran the test at different times of the day so I'm assuming when there is more of a drain because more are using the signal, the speeds would be less. Anyway, the download speed is between 2.26-14.47 Mbps & the upload speed is between 1.29-9.97 Mbps...seems like quite a range, but what do I know! With that info alone, I'm thinking that these speeds shouldn't vary much, so maybe there ARE settings that I should adjust, I just don't know what they are!
My laptop is 2 years old & even though I have it set to update automatically, I've never seen any of the Windows Updates containing any Driver updates. I know that drivers are a factor in lots of things, but I know from my 4 previous PCs that if Driver updates aren't done correctly/in the right order/installing the right version, etc., that things can get really bad. Do you think that this may be a driver issue, & if so, will you please recommend a program to use that will determine what drivers need to be updated & also will choose the correct versions FOR me to download? I'm intimidated by the driver sites, because they don't tell me which one I need...they show lots of versions, & I'm not qualified enough to make such an important choice. I'll paste my PC stats here:

Operating System
Windows 8.1 64-bit
CPU
AMD K140
40nm Technology
RAM
4.00GB DDR3 @ 676MHz (9-9-9-24)
Motherboard
LENOVO Lenovo G585 (Socket FT1)
Graphics
Generic PnP Monitor (1366x768@60Hz)
384MB ATI AMD Radeon HD 7340 Graphics (Lenovo) 191 °F
Storage
298GB Western Digital WDC WD3200BPVT-24JJ5T0 (SATA) 123 °F
Optical Drives
Optiarc DVD RW AD-7740H
Audio
AMD High Definition Audio Device

If you need any other info let me know. I really appreciate you taking the time to read my entirely-too-long post, but I tried to describe the issue as best as I could & I tend to babble when I don't know what to do.
Anyway, thanks again for your help, & any & all solutions are greatly appreciated! Please use LOTS of detailed instructions, though!
Gratefully,
Nuts4Mutts :confused