Whenever data is inserted in Stata, it's copied into the RAM memory of the computer. Generally, some of the changes are not on the permanent side and are not saved. So, these changes are lost when you reopen the Stata session. You can enter the data into Stata in various ways. One of the most effective way is as follows:
Use E:\Stata1\t1 less India pwt 80-2010.dta, clear
The option at the end of the code,
clear, makes Stata read the dataset again before you open another data file.
Another option with limited variables in the dataset is as follows:
use country year using "t1 less India pwt 80-2010 . dta" , clear
In order to read data in Stata, it has to be converted into a format other than Excel. Also, save the data ...