I believe some downloads from Websites accident to get Daugava pop up many times. I uninstalled Daugava and remove it from Chrome. I also use Window defend to remove many threats. But they might be not removed completely because the stupid ads by Daugava still appears!!! I google and found this image: from that article is quite similar as mine!!!??? That article saying that it is an adware? What the hell it is? So, I think i have a malware. Hey, guys, can you help me???

Sleepless would be best to answer your question.
I just used Malwarebytes AntiMalware to remove Super Optimizer, Delta-homes, do-search, Elex Hijacker, omniboxes, searchonme, CrossRider, & Adware RocketSale from Windows 8. I also ran CCleaner to clean up both the browser cache & registry.

I don't recommend SpyHunter as you can only analyze with the free version & it's difficult to uninstall.

I have used these in the past, but be careful and look at what they ask to fix. If you have special programs installed, they can turn up as false positives.

Junkware Removal Tool: Junkware Removal Tool Download

adwcleaner AdwCleaner Download

Has your problem been solved? Daugava is an ad-supported application that often enters the PC stealthily by being bundled with other freeware. You can perform a scan of your system with the free version of Malwarebytes and then delete all the threats detected. Or follow the instructions in the posts below to manually get rid of the adware.
Remove "Ads by Daugava" virus (Easy Removal Guide)
How to Remove Daugava Ads? – Adware Removal Guide | Uufix Security How-to Guides

Good luck.