I can not access data on pen drive

try other usb port, or other computer and see whether the hdd is detected. If still not, try to go to device manager ( http://www.computerhope.com/issues/ch000833.htm ), and then assign a drive letter to the hdd. After that, try to access it from Computer, if not able to access it, format it (use quick format) and then use asoftech data recovery program to recover your files.

try other usb port, or other computer and see whether the hdd is detected. If still not, try to go to device manager ( http://www.computerhope.com/issues/ch000833.htm ), and then assign a drive letter to the hdd. After that, try to access it from Computer, if not able to access it, format it (use quick format) and then use this program to recover your files.
http://www.asoftech.com/adr/

try other usb port, or other computer and see whether the hdd is detected. If still not, try to go to device manager ( http://www.computerhope.com/issues/ch000833.htm ), and then assign a drive letter to the hdd. After that, try to access it from Computer, if not able to access it, format it (use quick format) and then use asoftech data recovery software to recover files.
http://www.asoftech.com/adr/

try other usb port, or other computer and see whether the hdd is detected. If still not, try to go to device manager ( http://www.computerhope.com/issues/ch000833.htm ), and then assign a drive letter to the hdd. After that, try to access it from Computer, if not able to access it, format it (use quick format) and then use this program to recover your files.
http://www.asoftech.com/adr/

Check in Disk Management to see if the file system is corrupted or it is working..You can tyr re-scanning device....

Try this,

1. Click Start, click Run, type compmgmt.msc, and then click OK.

2. On the console tree, click Disk Management. The Disk Management window will appear.

3. On this disk management window, you can see some drives including the portable drive. Right
click on your portable drive and click change drive letter and paths.

4. Then a assign a new drive letter which is not being used by any of your drives in My Computer.

5. Finish assigning the new drive letter your portable drive will show up in my computer with
other drives

Hope it works for you

Is your pen drive heating ?

Click Start, click Run, type compmgmt.msc, and then click OK. 2. click Disk Management. The Disk Management window will appear.
3. On this disk management window, you can see some drives including the portable drive. Right click on your portable drive and click change drive letter and paths.
4. assign a new drive letter which is not used by any of your drives in My Computer.
5. After assigning the new drive letter your pen drive will show in my computer.

Trouble:
You may have faced a problem when you insert your pen drive and it gets detected very easily but it doesn’t show up as a drive icon in My Computer. The Computer detects the pen drive but data on pen drive is not visible as the pen drive is not visible in My Computer (Explorer).
This problem occurs mainly when windows XP fails to allocate a drive letter to your portable drive(pen drive). It occurs mostly with new pen drives connected to your computer for the first time. If you face such problem then it may not be the pen drive’s fault, rather it may be windows trouble.

If Problem Fix:
Fix:
You can fix this issue by following some simple steps given below.
1. Click Start, click Run, type compmgmt.msc, and then click OK.
2. In the console tree, click Disk Management. The Disk Management window will appear.
3. On this disk management window, you can see some drives including the portable drive. Right click on your portable drive and click change drive letter and paths.
4. Now a assign a new drive letter which is not being used by any of your drives in My Computer.
5. After assigning the new drive letter your portable drive will show up in my computer with other drives

my pen drive get detected but i am not able to format and copy things to my pen drive