On a budget? Before you schedule Computer Repair visit or bring your PC for cleanup, I suggest you to try few famous and free programs to get rid of the pests yourself.
Run this first (in Quick or Full mode):
My Favorite: Malwarebytes Anti-Malware – download here
This program is small and updates quickly. It's paid version has one of the best real time malware protection available.
After Installation and update, select Quick or Full scan and click Scan. If any problems found, program will offer to get rid of them.
Run this second:
Spybot – Search & Destroy – download here
During Installation deselect "Use system settings protection (Tea Timer)". From my personal observation, Tea Timer could cause compatibility issues with other programs.
After post installation wizard launches, click next until you see "Search for updates" and click on it. Updater will offer several locations, just click on any of them. Next click on download. After download finishes, S&D is restarted and you can exit the Updater. Now its ok to click on "Check for problems". If offered to remove Temporary Files, click Yes. This scan may take a while. When done, you will be offered to fix the problems found.
Although these two programs alone will not guarantee malware free PC, they are great start. If you use your Computer for any kind of financial transactions, such is online shopping and banking, I'll still suggest you have your PC checked and/or cleaned by professional.