Hello my name is XXXXX XXXXX I will be happy to assist you.
I am sorry to hear what happened to your computer.
I am going to give you some general things to try but since I do not know the exact infection you may or may not have we will have to see how it turns out.
I am going to provide you with some free tools that you will need to use as well.
First download the following programs and install.
Download Revo Uninstaller at the following site:http://download.cnet.com/Revo-Uninstaller/3000-2096_4-10687648.html?tag=dre
Just click the green download button on the left hand side.
Next download Malwarebytes antimalware:
Click on the following link. On the page click download latest version on the top right.http://www.filehippo.com/download_malwarebytes_anti_malware/
Once you download and install both of those do the following.
Restart your computer, as soon as it begins to restart keep tapping the F8 key on the keyboard.
When you get to a prompt choose safe mode with networking.
Next click start and choose control panel and choose uninstall a program under programs.
Next when the list of programs shows click on the top of the installed on column to sort the programs in order of most recently installed as shown in this picture below.
Basically what you want to do is uninstall anything that was installed on the day of or after the incident that you do not remember installing. These may be things like pc cleaning programs, download managers, tool bars.
If a program wont un-install you can open the Revo uninstaller program I gave you and remove it with that. Some of these can be very difficult to remove which is why I gave you that.
After you uninstall the programs that were installed you need to do a scan with malwarebytes.
Open the program and do a full scan (This may take up to an hour or longer in some cases). After it's done, press ok, then click the show results button in the lower right.
On the next screen, check all the boxes and then press the remove selected button to remove any infections that it found.
Once finished reboot into normal mode and open malwarebytes and do one more quick scan. If it is showing infections still then you likely have more issues so make note of what infections it tells you that you have and you can report back to me with that information.