[Gen8, Gen9, Gen10 Q&A, Help & Troubleshooting] Talasa:
So... I have an Archos 55 and well, root is dangerous, particularly when you're being annoyed with pop up adverts and want to get them gone.

TL;DR:

So basically this all started when I found that web pages and adverts were just opening. Whether I was using the device or not, they'd just magically appear, sometimes ten at a time, accessing the internet at will. I was not best pleased as I have not long purchased the phone, but true to form, Archos have no idea what customer service means, so I was left to attempt to remedy the situation myself. Ordinarily, I would have just formatted and reinstalled the O.S, I do that with linux all the time alas I knew that was difficult.

Instead I sought to find out what exactly was causing the adverts. I deleted all the apps I had installed, but still the adverts kept coming. I did a factory wipe. Still with the adverts. At this point I was a bit stuck, so I grabbed an anti-virus app. It showed a few things that were causing problems including one trojan, under com.android.settings (or something to that name). I made a few enquiries and needless to say, this wasn't a false positive, but it had meant that I had a trojan...and I really don't like trojans. Cue the rage and the not thinking properly as I deleted com.android.settings without making a backup thinking... "shouldn't be too hard to put back"...oh how wrong I was...

I of course tried to make amends by grabbing a "copy" of settings from another site (and possibly a different phone) but I was told that it was ROM and no amount of permission changing was going to change that (I tried and I apparently failed, I may have possibly been doing something wrong, but I don't think my chown/chmod skills are `that` shabby).

The problem:

- No access to settings. Settings doesn't exist. (No access to USB Debugging either because that requires tapping the about phone bit and guess what...)

- Can't install apps as something has "Stopped".

- No access to WiFi

- Using Linux (Ubuntu something or other...15 I think).

- Mobile Tinkering Newb (But I'm not totally tech illiterate).

I do have access to fastboot mode apparently.

So what I think I need is a way to reinstall lollipop 5.1 so I can get back to square one, without (at least initially) using ADB (because I've tried and my device just refuses to show). I've also tried a few "needrom" things but, of course, they don't work because linux.

If anyone could possibly help me, I would be greatly appreciative in any way. I just want wifi back really. (I can see that wifi works and a network is available I just can't edit the settings to access it). If I can provide more information, please ask and I shall provide.

[SOLUTION]

Back up your device <- Essential

Grab a rom from NeedRom

Enable Fastboot.

Enable USB Debugging etcetera.

Use custom software (provided by NeedRom) (I know this seems dodgy but you try anything when you're desperate enough and this works so...if you're worried then take precautions and make a backup of your own phone first.) to open up the .pac file. Check where the files have been opened up to.

Copy the files to a more stable area (i.e from Temp to your Data drive), they should be in .img format as .pac basically appears to be some kind of archive that groups them all into one.

Use Fastboot (you might need to enable this so make sure you do it) and flash the .img files to the phone and sparse them to about 250MB.

Restart the phone.

Check phone works properly.

If works properly, consider donating to NeedRom.