Yes.
Because of the fast changing market, differences in coverage, and protection philosophy we recommend using more than one scanner to provide additional layers of security, this is sometimes called security in depth. No one single software application can be expected to cover every possible spyware or unwanted program or vector of attack. No one can promise 100% safety and if they are making that promise, you should consider avoiding that program. One possible solution is to buy a commercial program and using a freeware one to maximize protection but minimize cost. Commercial programs, like our own, have dedicated and paid anti-spyware specialists who are available to help you out of a problem step-by-step. Freeware programs cannot offer this help and guidance. Be careful though- many rogue programs often try to pass themselves off as reputable freeware programs when in reality they actually infect your computer and try to get you to buy the application.

The bottom line, using two programs does help maximize coverage and safety. Even so, never be lulled into a false sense of safety. No system is fail safe and again avoid any company that makes claims like that.