Is Regtask a good and trusted program?
RegTask is considered by some users to be a malware spreading trojan. However, it's best to scan the download archive in VirusTotal website. The uploaded package will be scanned against known antivirus solutions.
I have downloaded then uploaded the package for you to see the results of the scan at the following address: https://www.virustotal.com/en/file/d09d0499acfcee89e0e7d49c92d45237e91369dc2d7f3c8ac6dba53ece0fbc94/analysis/1390612365/
The scan result displays 7 possible infections. I advise you to stay away from this program. CCleaner is a better and safer solution.