FT232R eeprom problem .. how to make PC recognize it
Is enumeration failing, or is just recognizing an device it doesn't has drivers for? (Unknown device)

If enumeration is failing, something in the hardware is broken. This could be a damaged chip (make sure you always power the chip completely , so don't let VCCIO be unpowered if you power VCC). 

If you're recognizing a device that's unkwown, it may be that Windows can't match a driver. In the EEPROM settings there is a VID and PID. These are manufacturer and product ID's, which are specific for each chip and corresponding drivers. The driver you downloaded match those.
There is an option to change these so you take the drivers of FTDI but change the .inf files to your own brand name. This means you could rename 'FTDI Virtual Serial Port' to something else.
If you don't have appointed him a driver, Windows doesn't know what to do with the device. Windows doesn't figure out by himself that the drivers for the original FTDI VID/PID's are good.

I suspect that this is happening. You could:


Desolder EEPROM and fit a new one (but if that's the RL edition, it's internal so not possible)
Try to see if FTPROG or the other EEPROM program utilities of FTDI still recognize it. If so, try to erase the configuration, don't touch the VID/PID settings :-)
Look up the VID/PID in Device Manager and make your own driver for it. It's in the details tab, and search for a property that clearly contains a value with 'VID' and 'PID'. Typically, Hardware Ids. The original FTDI settings shows me:
USB\VID_0403&amp;PID_6001&amp;REV_0600 (taken from a Arduino FT232RL)


Take the different VID and PID (stock is VID=0403, PID=6001) and adjust the .inf files correspondingly. There are some tutorials on the FTDI website and around the web on how to do that (I have done it once by paper, and forgotten what was exactly required). Appoint Windows to use this driver and it should be recognized again. Try FTPROG again.

If that doesn't work, I think your chip may be dead.

(oh by the way, short explanations only make guessing and answering harder)