Those do not determine if your computer is infected with something. As for the first problem can be keyboard key is broken and causing the switch back and forth between application to (if it was wireless) try a set fresh of batteries.
You should have antivirus and a malware scanner on your computer. If you do not, simply go to www.filehippo.com and download AVG or AVAST! then download MALWAREBYTES. If your using Microsoft Security Essentials REMOVE IT, this is a placebo AV and does not work nearly as well as any true dedicated AV software. Run the FULL scan from your antivirus, then run the FULL scan of the Malwarebytes. THESE WILL TAKE HOURS TO DO. If they find anything follow the recommendations reboot and START AGAIN until your system is clean. WORST, if it is a RootKit, you would need to wipe drive (yes and lose data because any 'saving' of the data will transfer the rootkit as well) and a clean Windows install.
If nothing comes of doing this then download SPECCY to tell us what your system is and we can work through many of the common issues (could be simply you didn't put enough fans in to there is a ton of dust inside the case). Also provide the PSU and how many Watts it can handle.