Dell Support remotely removed my FireFox home page, can I get it back?

What was your home page? You can set it via Settings > Home If Dell wiped the history and unless you made a backup of your profile it will not be that easy. If Dell made a new install of Windows for example, very difficult, what did Dell actually do. Remote access is always a bit of a concern as all your data can be copied etc. and worse. Dell have a reputation to keep but the individuals that work there do not. Under Windows you can find any Profiles you may have had. Usually in C:/users/####yo#####u/etc.etc. In the address bar type [about:profiles] this will show you where your current profile is, you may also find other there which you can then access.