What do you mean by checking it? I'm not able to install it if that's what you're saying....not sure what's going on, but yeah...not able to reinstall .NET.
hmmm... not sure but this can be your problem... if the installed version was right, a reinstall will be very fast since nothing will happen... not being able to reinstall it mean problem...
I bet that you have a windows OS, so, do you have some restore point ? Maybe a restore point just before all your problem can help !
About the .net, i have know problem too recently... a game have install a old version of .net 2.0 ... and the previous version was the last of 3.5 ... because 3.5 modify some of the 2.0 files, i was obligate to install 3.5 again... but i was able to make it...
Lucky that you are not a modder, because without .net , you are nowhere...
I am not a windows expert, i hope that someone else can help you but if i was not able to install something critical like .net, i will be formating and reinstall everything... it is a extreme solution but it always work!!!
In conclusion, if you have problem with .net, forget the Impulse problem... they are related to these .Net... it is not really a Impulse problem... simply something wrong with your system!!!