after booting board not recognized

Topic: after booting, board not recognized

OS Windows XP Board: Nano w/ Atmega328 IDE Arduino version 0021

Uploading worked fine with COM3, using the latest FTDI drivers. However, after simply booting the PC :

(1) on USB plugin the board is not recognized: "USB-device unknown" (2) in the hardware manager only COM1 shows up, COM3 is lost. (3) the FTDI drivers for reconfiguring the "unknown device" to COM3 cannot be found. (4) uploading not possible (5) on attempted uploading, the verbose commentary is this:

Binary sketch size: 7046 bytes (of a 30720 byte maximum) C:\Programme\arduino-0021\hardware/tools/avr/bin/avrdude -CC:\Programme\arduino-0021\hardware/tools/avr/etc/avrdude.conf -v -v -v -v -patmega328p -cstk500v1 -P\.\COM1 -b57600 -D -Uflash:w:C:\DOKUME~1\BERNDL~1\LOKALE~1\Temp\build4404214121566558350.tmp\f_messung_04.cpp.hex:i

avrdude: Version 5.4-arduino, compiled on Oct 11 2007 at 19:12:32 Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/

System wide configuration file is "C:\Programme\arduino-0021\hardware/tools/avr/etc/avrdude.conf"

Using Port : \.\COM1 Using Programmer : stk500v1 Overriding Baud Rate : 57600 avrdude: ser_open(): setting dtr avrdude: Send: 0 [30] [20] avrdude: Send: 0 [30] [20] avrdude: Send: 0 [30] [20] avrdude: Recv: avrdude: stk500_getsync(): not in sync: resp=0x00 avrdude: Send: Q [51] [20] avrdude: Recv: avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

avrdude done. Thank you.

What can be done?