It's not an Opera issue, it's an adware infection. "Reimage", either for Windows or PCs, is a for-pay utility program usually promoted from within an adware program which typically arrives bundled with a freeware download. In some cases, Reimage itself is sometimes directly bundled that way. Either way, as @nrqj notes, you have an adware infection impacting at least your Opera installation and perhaps your basic system. The usual remedy in such cases is to start with a couple of reputable cleanup scanner tools like AdwCleaner, Malwarebytes, etc. Always download the cleanup tools from the maker's own site to avoid counterfeits. If the tools don't completely clear up the problem, you may wish to visit a reputable cleanup website for help from their volunteers (Malwarebytes, DSLR, Wilders, etc).