External Lacie Hdd Isn`t recognized

Hi there ,
So it seems It`s the first time when my general knowledge or my good old friend google can`t help me so I hope someone from this website will .
Right so this is what happened today :
I`ve upgraded my laptop`s ram today from 4gb to 8gb and I said hey , why not do a fresh install of windows as dell support center wasn`t loading up anymore .Anyhow I have a lacie 500Gb hard drive which seemed to work fine till now .
Right now , after the reinstall my hard drive just isn`t accesible anymore .
Basically i can see it in the devices and printers section , i can see it on disk management ( i also tried changing the letter etc , the partition is active i can see that it`s 500gb but i can`t acces any data ) and i can also see it on My computer as a partition but not as a storage device .
What does happen is after 2-3 minutes or so , a windows pop`s out to format the disk which i can`t even do , on my girlfriend`s laptop works very well .
Now this is extremely strange as i did nothing and all but reinstall windows , also i`ve updated to date .
Now i`ve also tried uninstalling the usb driver from disk management still no joy .
Anybody please help , this is the first time I can`t really manage something and it`s really buggin me .

Update on my post ... I did a format on the external hdd ntfs , same problem , my girlfriend`s laptop can see it , on mine it does appear in the devices and printers etc , but there is no access from my computer or any other means . Also tried fat format , seemed to work for a few minutes then started crashing after i try to create a folder in it or whatever ...