It probably installed along with something else as an option, always monitor downloads to see if they have a custom option, use that preferably as often you can refuse unwanted adware.
There's an excellent removal guide here: How to remove TheBrowser adware (Removal Guide)
More tools and tips here: Anti-Spyware/Malware/Hijacker Tools
thank you for your great assistance. I have seen no evidence that THE BROWSER has returned. Nicely done
Thank you for your prompt response
Glad that all is okay now...
All the Best,
Glad to help.