Do not download any apps, it's dangerous specially in windows... even if you could download the source code and compile it yourself just don't risk it and follow this easy method: You simply open your wallet.dat file, with any text editor of choice, and use ctrl+f to search for "name"" and if your wallet.dat file had any addresses, you will find them there. Now you just have to look at the format and you'll know. (If they begin with 1, it's BTC, if they begin with L, it's LTC...). Most have very recognizable formats. In the case of doubt, just enter the address in the block explorers you suspect the address belongs to look for any funds. This way you don't have to wait for it to sync to see if your wallet matches the client. And this is the trick I've been using when I found random wallet.dat files.