Windows/FF and IE aren't working right

I originally posted in the malware removal section and was told there was nothing showing it was from malware.

A few days ago I started getting error messages on Firefox this was the first error message: "Content Encoding Error

The page you are trying to view cannot be shown because it uses an invalid or unsupported form of compression.

Please contact the website owners to inform them of this problem."

I have gotten that error now quite a bit now, I've also started getting a security error message. When I tried using FF to upload files to my malware post the files wouldn't show up while using FF, but they did show up while using IE.

When I downloaded the programs from the malware "Read Me and Run me" post, the downloads didn't seem to download right as I had problems with the programs running and they said they weren't made for this PC and to find a version that can run on my PC. I had the same problem on both browsers. Also both browsers have become quite slow to load and sometimes not all it. I sometimes have to click stop then reload for the page to load. Webpages frequently don't load correctly, sometimes the images don't load or the page setup doesn't look right.
I hope someone has someone might know of a fix. Thank you for any help.

 

Sorry I forgot to add that information.
1. Windows 8.1 64bit
2. FF version 36.0.1 (As I was checking for the version FF started downloading an update, then the update failed)
IE update version 11.0.17
3. Avast
4.Error message: Secure Connection Failed

An error occurred during a connection to search.yahoo.com. SSL received a record with an incorrect Message Authentication Code. (Error code: ssl_error_bad_mac_read)

The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
Please contact the website owners to inform them of this problem.

I also noticed that sometimes the icons on this forum don't work right for me for ex. when I click the wrap quote icon it didn't work I had to go back and click quote on your message to quote you. Also on a forum that I help run the reply box doesn't appear anymore so there isn't a way for me to reply to threads or messages. I started having all of these problems after the first content error messages. Also Avast detected a file called delay.exe I don't know if it was a false positive or not and neither did the malware expert from the malware form but he said I should post here.

Thank you for your help

 

I went to both links for the content encoding error I tried to follow the instructions to manually delete the browser cache, but I wasn't sure what to do after I got to the folder jedifs5h.default it has more folders and 2 files in it.

For the secure connection error I didn't really see an error that matched the one I'm getting, I noticed it said it in the first section but the table of contents seemed to be about certificates which I haven't gotten warnings for. Should I follow the instructions for the certificate warnings anyways?

Thank you both for you help

 

At first I couldn't figure out how to use it since I was used to the start menu in the corner rather then the whole screen so it took me a while to get used to it, I'm still not sure if I like it though.

I tried to update manually following the directions but the update still failed, then it had a link to download the latest version which I clicked and it said I already have the latest version.
An error for FF popped up and said FF could not be updated because :"The integrity of the update could not be verified"

I was unable to find the file to be able to use that website. So I reran Avast to so if it would find it and it did though I can't find it in Windows explorer since the file location doesn't seem to say what drive it is on it just has \\?\volume at the beginning then a bunch of numbers, letters and symbols, then \oem\delay.exe at the end.

 

I just noticed Avast checked for software updates and I clicked to update FF and it seemed to of worked so far.