PCB Design :Plz suggest me any PCB design software for complex Circuits?

Actually i m working on Proteus Ares Professional 7.1 but the circuit is too complex , due too which my schematic is showing some errors . and offcorse i want to design it on a single layered PCB board . Suggest me how to autoplace the components in Ares ?

There is no magic way to autoplace the components in the best possible position, the autoplace does it kind of randomly so it is better to place them manually by looking in the connection lines and then try to route the board and move or rotate components to help routing.
There will still be cases where a single layer routing will not be possible so maybe a few jumpers will help or you have to use a double layer.

Also experiment with thinner track size, a thinner width will be routed easier but don't use too thin tracks for power supply lines.

If your question is how to use autoplace then you need to draw a yellow rectangular for the board edge (select the blue square icon and draw in the yellow layer) and then you will be able to use the autoplace function.

Alex

okie alexan lemme try ....thanx btw

The sucksess of PCB design depends upon placement, and this is one of the major skills you develop, by doing numerous designs. Those of us luck enough to start doing taped PCB designs soon learnt the importance of compnent placement. A autoplacement will not achieve the desired results without so many rules and constraints that youy are better of placing manually...

For single layered PCBs it should not be the matter of discussion that which PCB Designing software is good. I designed many single layered (including complex ones) PCB using ARES. Autoplacement and Autorouting is not always the best choice for good and compact design. If you manually do the placement and routing it makes a really good design...