Windows 7 - Slow start-up

At first, I noticed that my laptop increase the time it takes to start.. Usually it took only 40-45 seconds to boot..But now, it consume almost 2minutes until I see the desktop background..I decided to run a full system scan using Avira AntiVir Personal and detected a TR/Gendal.110629 trojan (now moved to quarantine). After that, I defrag the disk just to make sure that there are no bad sectors. But still it ain't coming back to normal. I wonder if the virus might be the cause of delay to start up.

Please help me regarding this issue..

Thank You!

Welcome
A clean boot will help you determine the cause
How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7
Download and make a full scan with malwarebytes, too.
Optimize Windows 7

Many factor leads to slow startup. Most common are conflict between security software. What are your other security software? Have you recently added some software? also disable unnessecary start up application. Leftover from uninstalled software also leads to problematic start up. Use ccleaner to clean the resistry. Don't forget to back up resistry. Also use ccleaner to clean junk files from the system. also use sfc /scannow command in comand prompt and see if there are some corruption in system file.