> microcontroller sends a set of data to the pc
> what is the probability of the data to get
> corrupted

Probability increases in case of intense EMI, also if transmission line is long and/or unshielded.


> how do i check if the data has
> reached safely.

Use somewhat like CRC check. For example,
http://www.modicon.com/techpubs/crc7.html


> can u suggest me as to the different kinds
> of device driver softwares [languages that
> are friendly to the H/W] avaliable??

You mentioned Watcom C++. I'm not familiar if it can build DOS applications, so I assume that you want a driver for Windows. If standard WinAPI communication functions are enough for you (eg., there's no need to flip parity for bytes being sent), you can do it with an usual Win32 (or even Win16) application.

Otherwise, a good tool for writing Windows (VxD) drivers is VToolsD from NuMega. Windows Driver Development Kit, which is included in some MSDN subscriptions, may also be used. I'm not sure but the latter may be cheaper.

==
Tomas