I can't do anything

I am not the most adept at computer problems :

This morning when using an application on my computer my firewall (Comodo) became very annoying with asking to allow applications that I had already told the firewall to always trust. I found a temporary solution continued using the application and logged off.

Later when I logged back on to my computer my firewall started asking about everything, and I realized I needed a permanent solution. The one I found was to reinstall Comodo. I went into the "Add or Remove Programs" and tried to uninstall Comodo.

This is when the message popped up that read "The Windows Installer Service could not be accessed. This can occur if running Windows in safe mode, or if the Windows Installer is not correctly installed. Contact your support personnel for assistance." I wasn't in safe mode, so I researched how to reinstall The Windows Installer Service using the message on the pop-up. Which ended up leading to this website:

http://www.msifaq.com/error/1719.htm

This website did not fix the problem. I went to one of the links the website gave, this one, and tried to follow the steps given. However, the System Restore was not working.


This is when my "Support Personnel" comes up with the idea "Hey we'll put your stuff on this external hard drive I have and move it to a new hard drive. As a bonus we'll upgrade you from Windows XP to Windows 7" (just the gist of what they said).

So we plugged the external hard drive into my computer, and nothing. It didn't show up. Not only that but the device manager wouldn't work so I couldn't find it that way either. Then he came up with Plan B: Put my hard drive and the external hard drive in his computer and transfer them that way. I decided I would try and make it easier when the time comes and make a list of all the programs I want and put it in a folder with all the Misc files I want. As it turns out I cant move, or paste files. I can copy, but not Paste. So I wrote the list and files down on pieces of paper.

Anyways, we are going ahead with Plan B but we want to know if you guys have any last minute solutions for us before we go ahead and do Plan B.

One last thing, my computer decided to disconnect itself from the internet and I can't use it, so it might be kind of hard to get any information you guys might need. I hope what I provided, a detailed account of what happened, is enough.