If I understand it correctly you are asking whether you could replace 26" wheels with 700c? I assume both have rim brakes.
Firstly you should do a quick check to ensure there is enough clearance for the 37mm tyre you want with 700c rims front and back. A 700c rim's radius is just over 3cm larger than a 26".
Because 700c rims are at a different distance from V/Canti brake bosses (used by most 26" wheels), generally you will have to use different brakes, which depend on what would the distance be between a 700c rim and holes on forks and rear brake bridge if available for caliper brakes. Generally the distance between fixing hole and centre of brake pads for racing caliper brakes is around 45mm, but longer reach brakes are
available.
If the existing use V brakes and you have to resort to caliper brakes then you will need different brake levers (or change brake lever setting if available). Adjustable/long reach V's are also available though rarely used and they will also require different brake lever (or lever setting if available).
You will also want to check the distance between the rear dropouts. Most 26" rear hubs are 135mm, while most 700c rear hubs are 130mm wide. Because quick release axles are typically 11mm longer than the hubs, a QR 700c wheel can generally be made to fit by introducing spacers.
If you want to replace the chainset you should choose carefully to ensure no clash, the chainline is reasonable, and doesn't cause problem with the front mech if there is one.
