make a shortcut that points to the directory that qb 4.5 is in. for the first one, point to the directory qb 4.5 is in and add qb.exe. for example,
c:\program files\qbasic45\qb.exe
for the second one, point to the directory that all the programs that come with qb are in.
example: (say all the programs are in the same folder as qb4.5.
c:\program files\qbasic45
that's it! just use the shortcut.