Recuva doesn't work in my PC

Hi,

I have installed Recuva (three versions), and each time I try to scan a harddisk drive ( C: or F: ), it stops immediately and shows at the bottom of the screen, the following message:

"The system cannot find the specified path" ( in Spanish )

I tried with Version 1.04. See the content of "Error_Log_4_9_2007.txt":

Recuva v069

===========

System Info: MS Windows XP SP2, Intel Pentium 4 CPU 2.00GHz, 1.0GB RAM, Intel 82865G Graphics ControllerDRIVEDESC FSys:1, BytsPSect:512, SectPClust:8, BytsPClust:4096, FRSize:1024, ClustCnt:14653280, MFTClustNo:0, MFTMirClustNo:786432

[18:42:53] ErrorNo: 3 OtherInfo:cundelete_recdrv2 Error No:536870916 ErrorInfo:Failed to read boot sector.

[18:43:11] ErrorNo: 3 OtherInfo:cundelete_recdrv2 Error No:536870916 ErrorInfo:Failed to read boot sector.

[18:43:15] ErrorNo: 3 OtherInfo:cundelete_recdrv2 Error No:536870916 ErrorInfo:Failed to read boot sector.

[18:43:32] ErrorNo: 3 OtherInfo:cundelete_recdrv2 Error No:536870916 ErrorInfo:Failed to read boot sector.

[18:43:58] ErrorNo: 3 OtherInfo:cundelete_recdrv2 Error No:536870916 ErrorInfo:Failed to read boot sector.

[18:46:3] ErrorNo: 3 OtherInfo:cundelete_recdrv2 Error No:536870916 ErrorInfo:Failed to read boot sector.

Then, with version 1.05, I had the same problem.

And finally today, with version 1.06, the content of file "Recuva_log[1_06_132][7-10-2007_16-35].txt" is:

[2007-10-07 16:35:28] [iNFO ] Recuva v1.06.132

[2007-10-07 16:35:28] [iNFO ] System Info: MS Windows XP SP2, Intel Pentium 4 CPU 2.00GHz, 1,0GB RAM, Intel? 82865G Graphics Controller

[2007-10-07 16:35:32] [ERROR] El sistema no puede hallar la ruta especificada.

[2007-10-07 16:35:37] [ERROR] El sistema no puede hallar la ruta especificada.

The system cannot find the specified path (in Spanish)

Thanks in advance for any help on this.

MORE DATA: I have plugged an external USB Hard disk. Recuva seems to work fine with it: scans the disk and finds deleted files! But still cannot scan the two internal HD's...