Windows admin vs standard user

COMPUTER ONE (desktop, no brand, Win 7)

1) I installed Soulseek from an Admin profile and started to use in the same profile. Everything fine.
2) Then — let's say one month later — I decided to create a standard user.
3a) If, with the standard user profile, I launch the program as standard user I get "Soulseek's installation is corrupt or missing. Please reinstall Soulseek".
3b) If, with the standard user profile, I launch the program as Admin it works.

COMPUTER TWO (laptop, Asus, Win 7, original installation)

1) Same
2) Same
3a) Same
3b) Same as 3a

Any ideas?