allroad said:
does the main computer need to be connected via network cable to wirless adsl router or can it be connected wirelessly via a pci wireless card
The main computer does NOT need to be connected up using wires. But its better if you have it connected using wires. You may notice, at times, your connection will drop using wireless equipment or may be you wanted to change settings on the Router, its better to have a direct connection.
allroad said:
also if connected to 1mb adsl will the 1mb connection suffer and become slower if the main comp is connected via wirless
Not really, your may notice at times the speed drop slightly (e.g. when the Microwave is switched on or when your DECT phone rings), but on a general note, the wireless connectivity shall always try to give you the maximum connection speed that is available.
One thing to note though, having a wireless connection does NOT provide you the best connectivity 24/7. There is a higher chance of network performance dropping, loosing connection with wireless then having a wired up solution.
The distance between the wireless router and the main computer also has a great part. If the distance is not that much, not going through walls, not sitting next to a DECT phone, then you shall probably have the optimal solution. But otherwise performance tends to dither.