I know it is a bad idea to install more than one antivirus in the machine. But what about installing an antivirus + anti malware like Spybot, Ccleaner etc? should be no issues, right?

I meant to ask from those who have tried it

Yes, at times it does seems good to have 2 software doing individual protections. I've tried Norton Ant-Virus, TrendMicro, McAffee all with CCleaner installed together.

But over the time it does pose some problems, like when anti-virus reporting a file having some problems but CCleaner doesn't and sometimes vice versa too.

Be careful at what those anti-virus or anti-malware is reporting, sometime its just an alert instead of a real threat. These alerts is just to notify you that certain files cannot be validated due to no information or less information was available in their respective database server, as such its only an alert. If its was a real known threat then it would automatically be either removed or quarantine.

Now take into considerations of the "Heuristics" features, these scanner does sometimes report or gives alerts that are false alarm, but you can't blame them due to the constant rises of viruses & malwares in internet this days.

As I've always reminded all my users, pre-cautionary approach and lots of common sense is required. "THERE'S NO FREE LUNCH!"

I would suggest a good anti-virus program like Norton Security Deluxe with built-in anti-malware & anti-spyware, with a single interface you can be sure of the reliability & trust of it.

But still if you think that having 2 is better then it makes no harm doing so, as long as it doesn't conflicts with each other like both are also an anti-virus programs..... you know what I mean rite.

Happy computing.