PC does not recognise ft232r (usb<->rs232 converter) on a custom board

So I have to make a USB to RS232 converter using ft232r on a custom designed board. Soldered everything, connected to the PC, installed the drivers and then ran the provided test program. It gave the following error:

Failed to initialize onboard COM tester

as a reason for this error is specified that the PC does not recognize the motherboard COM ports. Frankly I'm not at all acquainted with the COM ports, so I don't know what to do now. Any suggestions?
For what it's worth the test app says it can use only COM1 and COM2, but Device manager tells me my device is at COM7, but at Location 0. That is, if I'm reading it correctly. Don't know how to change the COM.
Another strange thing is that whenever I unplug and then plug again the device, windows prompts me to install the drivers again, as if they were never installed in the first place. I must have installed them like 8 times by now and I'm afraid I'm just clogging my C drive. How to verify everything is alright with the drivers?
I'm using winXP if that matters.
Another version of the test program gives me "Failed to initialise the tester", which means the device cannot be seen or recognised by the PC. Again, I have no idea what should be my next step.

I have checked the board like 5 times and everything is soldered correctly.

To remap a com port:

Start Device Manager
Go to Ports (Com & LPT)
Right-click a port and select Properties
Select Port Settings tab
Click Advanced
Change the port number

You will need to remap Com 1 or 2 away first, then remap the one you want to the now-free number.

As to the rest, no idea but when I hear FT232R driver problems the first thing I think is: is it a genuine chip or a fake?