We will be happy to offer you this Desktop application (in C++ or C#). Suggest to split it to 2 projects. See my comments. When there isn't a comment, that means we can do it.
1. Software Should Clean (TEMP, %TEMP%, PREFETCH,).
2. Software Should Clean Browser Surf History, Tracking Cookies, Download History and remove Browser Extension Manually.
3. Software Should remove Riskware, Malware and Trojan - require a separate project
4. Software Should have Add Blocker which should block ads across system including all browser. - require a separate project
5. Software Should be integrated with payment gateway so that user can renew the subscriptions manually. - we have an integration engine with Paypal
6. Software should have Login, Signup, Reset Password options.
7. Same credentials can be used to login to account on web.
8. Software should send the desktop notification for renewal or cleaning the system if not cleaned in last 7 days.
9. Software should have trial version for 30 days.
10. Software should be compatible on all versions of windows.
11. UI of the Software should be attractive.
12. Software should have connect to technician button which should redirect the technician chat page.
13. While installing software should have option to add start application at system start up time
14. Software should be lightweight and should not effect system startup time.
15. After running the system cleanup, Software should ask for system restart if required.