For one of the requirement I am working on, I need to make sure that the end users are disabled from uninstalling the existing apps and installing new apps from store.
Any pointers in this regard is really appreciated.
if they have admin rights they can uninstall any app.
if you place this system on the net | store there is no way to block the store for users... I would lock the hdd space but you didn't give us all the info
echoing the approach Edwin mentions, if you are creating logins on business computers (you didn't state the use), you might go a step further and only give them GUEST login access, which also locks out the APP STORE access, or pops up a message requiring an administrator (you!) to come to their PC and type in your password to access the APP STORE for purchases. If this is an educational environment, the same thing goes. Giving business or educational users in either environment STANDARD login access invites them to do some damage to their computers that will cause you a lot of time and grief to fix.
GUEST login access makes it really hard for an occasional user to scramble their Windows settings, delete apps or folders or files. That's why public & University Libraries, and Senior Centers (I've worked on both) often use this method to lock out folks looking to cause damage or mischief on the computers you are setting up and ostensibly managing. The folks who administer these type of computing environments have now had decades to figure out the best methods, and besides using something like STEADY STATE, which doesn't work all that well in modern Windows versions, it's your best bet for protecting computers you are deploying.