lost capability to connect to other drives on network

i have just added a laptop OS windows 7 to my home network, everything was ok , i could transfer files, use printer until the weekend, now i cant connect to any drive on a different pc, and get error saying can not connect, my man pc sees the laptop fine, and vice versa , all the drives are shared and both in homegroup, laptop is wireless and connects to internet fine, i tried it hardwired as well to no avail. turn all firewalls and security off to see if that was stopping it , still no joy, bit odd as ive installed nothing new , just couldnt connect after rebooting the laptop , any help will be greatly appreciated, thanks

::BUMP::

I'm having the same issue. Mine's been going on a lot longer though.

In order to share drives with other machines you need to use both the regular permission settings and also the Security settings need to be enabled for the drive.

To share the entire drive:
Open My Computer -> right click Local Disk D or which ever drive letter your drive is using -> select Properties -> select Security tab -> click Edit button -> click Add button -> enter the name of the User you want to set Security permissions (it is the same user name you've set the sharing permissions for, ex. Everyone will set the read permissions to every user. Put check marks in the boxes for full access and control -> click OK hit apply-> select the desired permissions -> click OK -> wait while permissions are set -> and your Done.